OPINION
¶ 1 The family of Ruth Golonka initiated this products liability case against General Motors Corporation (“GM”) after Mrs. Golonka was tragically killed when her idling GM truck shifted into reverse and struck her as she stood behind the truck. A jury found GM at fault for negligence and strict liability information defect, and awarded compensatory and punitive damages. GM appeals from the subsequent judgment, arguing that the court erred by denying GM’s motions for judgment as a matter of law and for a new trial, and by making certain evidentiary rulings.
¶ 2 To resolve this appeal, we must answer the following questions, among others: Could the jury have consistently found GM not at fault for strict liability design defect but liable for negligent design? Does Arizona continue to recognize the so-called “heeding presumption” used in information defect cases? How do evidentiary presumptions operate in civil cases? Did the trial court properly apply the heeding presumption in this case? After answering these questions, we decide that the trial court erred by instructing the jury on the heeding presumption. Because this error prejudiced GM’s substantial rights, we reverse and remand for a new trial.
FACTUAL AND PROCEDURAL HISTORY
¶ 3 On April 17,1997, Ruth Golonka pulled her 1987 GM Sierra truck in front of her neighbor’s curb to load chairs into the truck bed. She attempted to shift her transmission into “park” but, according to GM, misshifted to a position between “park” and “reverse.” Before exiting the truck, Mrs. Golonka did not turn off the engine, remove the key, or set the parking brake. Mrs. Golonka walked to the rear of the truck and dropped the tailgate to load the chairs. The truck then shifted into “reverse” and backed over Mrs. Golonka, killing her.
¶4 Mrs. Golonka’s husband and children (“Plaintiffs”) brought this wrongful death lawsuit against GM based on theories of strict product liability (defective transmission design and an information defect) and negligence (transmission design and failure to warn). Plaintiffs sought both compensatory and punitive damages.
¶ 5 At the conclusion of the subsequent jury trial, GM moved for judgment as a matter of law (“JMOL”) on the non-design aspects of each claim, arguing that Plaintiffs had failed to present evidence that any information defect or failure to warn caused Mrs. Golonka’s death. GM also moved for a JMOL on Plaintiffs’ request for punitive damages. The court denied both motions.
¶ 6 The court submitted a single verdict form to the jurors that asked them to check a box to indicate whether GM was “at fault” or *580 “not at fault” on the negligence claim. The form did not require the jurors to state whether they found GM liable for negligence based on its transmission design, the failure to warn of mis-shifts, or both. Assuming the jurors found GM “at fault” for negligence, they were then instructed to assign percentages of fault between Mrs. Golonka and GM.
¶ 7 Unlike its treatment of the negligence claim, the verdict form distinguished between the two theories underlying Plaintiffs’ strict products liability claim. Specifically, the jurors were asked to check a box to indicate whether GM was “at fault” or “not at fault” for the products liability claim alleging defective design. The form then instructed the jurors to check a box to indicate whether GM was “at fault” or “not at fault” for the products liability claim alleging an information defect. Assuming the jurors found GM at fault for either or both claims, they were then instructed to assign percentages of fault between Mrs. Golonka and GM.
¶ 8 The jurors found GM at fault on the negligence claim and assigned 40% of fault to Mrs. Golonka and the remaining 60% to GM. The jurors also found GM at fault on the products liability claim alleging an information defect and assigned 50% of fault to Mrs. Golonka and the remaining 50% to GM. But the jurors found GM not at fault on the products liability claim alleging defective design. The jury awarded compensatory and punitive damages to Plaintiffs. After the trial court denied GM’s renewed motion for JMOL and its motion for new trial, this appeal followed.
STANDARD OF REVIEW
¶ 9 We review de novo the trial court’s denial of GM’s motion for JMOL.
Monaco v. HealthPartners of S. Arizona,
DISCUSSION
¶ 10 GM argues that the trial court erred by (1) denying GM’s motion for JMOL because Plaintiffs failed to prove that any information defect or failure to warn regarding mis-shifts caused Mrs. Golonka’s death and (2) denying GM’s motion for new trial because a jury instruction incorrectly imposed a burden on GM to disprove that Mrs. Golonka would have heeded any warning about mis-shifts.
¶ 11 Each of these contentions relates solely to the information defect and failure-to-warn theories of liability. But if the negligence verdict was grounded on Plaintiffs’ assertion that GM negligently designed the truck transmission, we will affirm regardless of any error relating to the information defect and failure-to-warn theories.
See Murcott v. Best Western Int’l, Inc.,
A. Basis of negligence verdict
¶ 12 GM argues that the jury necessarily rejected Plaintiffs’ theory of negligent design because it found GM not at fault on the strict products liability claim that was based on defective design. Consequently, GM contends, the jury must have based its negligence verdict on GM’s failure to adequately warn Mrs. Golonka about mis-shifts. 1 *581 Plaintiffs respond that the design-based theories of recovery are not mutually exclusive, and the jury’s rejection of the strict products liability theory did not necessarily reflect a rejection of the negligence theory. In order to resolve this issue, we examine the interplay between these theories.
¶ 13 A manufacturer is strictly hable for injuries caused by use of any product that was in a “defective condition unreasonably dangerous.”
Dart v. Wiebe Mfg., Inc.,
¶ 14 Under the “consumer expectation test,” the fact-finder determines whether the product “failed to perform as safely as an ordinary consumer would expect when used in an intended or reasonable manner.”
Id.
at 245,
¶ 15 The consumer expectation test works well in manufacturing defect eases because consumers have developed safety expectations from using properly manufactured products of the same general design.
See id.
at 244,
¶ 16 In order to succeed on a negligent design claim, a plaintiff must prove that the manufacturer acted unreasonably at the time of design or manufacture in light of the foreseeable risk of injury from use of the product.
Id.
at 246-47,
¶ 17 After noting the confusion generated by application of the risk/benefit analysis factors in both strict liability design eases and negligent design cases, the supreme court in
Dart
distinguished the theories.
Id.
The court pointed out that the central focus of inquiry in strict liability design cases is whether the
product
was unreasonably dangerous, while the focus in negligent design cases is whether the manufacturer’s
conduct
was unreasonable in light of the foreseeable risk of injury.
Id.
Consequently, in a negligent design ease, the risk/benefit analysis factors are used to assess the reasonableness of the manufacturer’s choice of design in light of the knowledge available at the time of design or manufacture.
Id.
at 247-48,
¶ 18 With the above-explained precepts in mind, we now decide whether the jury’s rejection of Plaintiffs’ strict liability design claim necessarily reflected a rejection of the negligent design claim. We start by examining the trial court’s instructions to the jury on each claim.
See Toner ex rel. Toner v. Lederle Laboratories,
¶ 19 The court instructed the jury, in pertinent part, as follows:
Negligence Claim
Negligence is the failure to use reasonable care. Negligence may consist of action or inaction. Negligence is the failure to act as a reasonably careful person would act under the circumstances.
Product Liability Claims
1. Claim for Design Defect
A product is defective and unreasonably dangerous because of a design defect if the harmful characteristics or consequences of its design outweigh the benefits of the design.
A manufacturer or seller is presumed to have known at all relevant times the facts that this accident and this trial have revealed about the harmful characteristics or consequences of the product’s design, whether or not the manufacturer or seller actually knew those facts. If you find that it would not be reasonable for a manufacturer or seller, with such presumed knowledge, to have put this product on the market without changing the design, then the product is defective and unreasonably dangerous because of a design defect.
A product is also defective and unreasonably dangerous because of a design defect if it fails to perform as safely as an ordinary consumer would expect when the product is used in a reasonably foreseeable manner.
The first and second paragraphs of the strict liability design defect instruction required the jury to utilize the risk/benefit analysis and impute “hindsight” to the manufacturer, while the third paragraph sets forth the consumer expectation test.
¶20 Plaintiffs argue, and the trial court agreed, that because the court properly instructed the jury to assess GM’s conduct in deciding the negligent design claim, and instructed the jury to assess the quality of GM’s product in deciding the strict liability design claim, the claims are distinct, and the jury could have consistently found GM at *583 fault for negligent design and not at fault for strict liability design defect. We disagree.
¶ 21 We assume the jury followed its instruction to employ a risk/benefit analysis in deciding whether GM was at fault for strict liability design defect.
Hyatt Regency Phoenix Hotel Co. v. Winston & Strawn,
¶ 22 Because the xxniverse of knowledge attributed to GM under the rejected strict liability design claim included what GM actually knew at the time of design or manufacture, it would have been inconsistent for the jury to have found GM at fault for negligent design. Specifically, the jury could not have consistently foxrnd that even with the benefit of hindsight, it would have been reasonable for a manufacturer to have placed GM’s transmission on the market, yet GM “fail[ed] to act as a reasonably careful person woxxld act xrnder the circumstances” by doing just that.
See Gomulka,
¶ 23 The Ninth Circuit’s decision in
Toner,
relied on by Plaintiffs, does not persuade us to reach a different result. In that ease, plaintiff Toner had been paralyzed after being vaccinated with Tri-Immunol, a vaccine manufactured by defendant Lederle.
Id.
at 511. Toner asserted claims against Lederle for negligence, strict products liability, and breach of warranty, primarily contending that Lederle had failed to develop and market Tri-Solgen, an alternative and safer vaccine.
Id.
Lederle asserted that it was immunized from liability because Tri-Immixnol, like other dnigs, is unavoidably unsafe and it is therefore permissible to market that drug despite its inherent risks.
Id.; see
Restatement (Second) § 402A cmt. k (recognizing defense to strict liability claims under certain conditions for manufacturers of unavoidably unsafe products). The trial court instructed the jury to follow the consumer expectation test in deciding whether Tri-Immunol was in a “defective condition, unreasonably dangerous.”
Toner,
¶24 On appeal, Lederle argued that the jury’s rejection of Toner’s strict liability claim necessaiily meant that any defect in Tri-Imimxnol was unavoidable, which was fatally inconsistent with a finding that Lederle was negligent in its manufacture or distribution of the vaccine. Id. To resolve the issue, the Ninth Circuit examined both Idaho law and the trial court’s instructions to the jury. Id. at 513. The court noted that under Idaho law, a plaintiff may proceed under a negligence cause of action even if the “unavoidably unsafe” defense immunizes a manufacturer from strict liability. Id. at 512. Consequently, and in light of the instruction to the jxxry on the consumer expectation test, the court held that the verdicts were consistent because “[i]t is reasonable to read the special verdicts as saying that Lederle’s failure to develop the Tri-Solgen vaccine was unreasonable conduct, although *584 the danger posed by the product [Tri-Immunol] itself was not greater than an ordinary consumer would reasonably expect.” Id. at 513.
¶ 25 Toner is distinguishable from the case before us because the jury in Toner was only instructed to apply the consumer expectation test in determining whether Tri-Immunol was in a defective condition and unreasonably dangerous. Because the court did not instruct the jury to employ a risk/benefit analysis, the jury did not decide that with the benefit of hindsight Lederle failed to act as a reasonably careful person would act under the circumstances by placing Tri-Immunol on the market. Thus, the Ninth Circuit was not faced with reconciling such a decision with the jury’s acceptance of Toner’s claim that Lederle acted unreasonably by placing Tri-Immunol on the market. The lack of a risk/benefit analysis jury instruction in Toner distinguishes that case from the one before us.
¶ 26 Finally, we reject Plaintiffs’ contention that the jury could have consistently rejected the strict liability design claim and accepted the negligent design claim based on a finding that GM’s transmission design was “state of the art.” See Ariz. Rev.Stat. (“A.R.S.”) § 12-683(1) (1992) (providing affirmative defense to products liability claim based on inadequate design if design state of art at time product first sold by manufacturer). The court instructed the jury that the “state of the art” defense applied equally to both the strict liability design and negligent design claims. Consequently, if the jury found the defense applicable to shield GM from fault under the strict liability design claim, the jury could not have consistently rejected the defense by finding GM at fault for negligent design.
¶27 In summary, when a plaintiffs claims for strict liability design and negligent design are factually identical, and the jury employs a risk/benefit analysis to determine that the manufacturer is not at fault for strict liability design, the jury cannot consistently find the product manufacturer at fault for negligent design. 3 Because that is the scenario in this case, the jury’s negligence verdict was necessarily predicated on Plaintiffs’ failure-to-warn theory. Thus, GM’s arguments relating to that theory are viable, and we now address them.
B. Denial of JMOL on failure-to-warn claims
¶ 28 GM argues that the trial court erred by denying the motion for JMOL on the failure-to-warn claims because Plaintiffs did not prove that any deficiency in GM’s warnings caused Mrs. Golonka’s death. To prove causation, Plaintiffs were required to present evidence that if GM had issued a proper warning, Mrs. Golonka would have
*585
taken precautions to avoid the accident.
Gosewisch v. Am. Honda Motor Co.,
¶29 GM contends that we should follow the supreme court’s decision in
Gosewisch,
which affirmed the trial court’s refusal to give a warnings instruction in a products liability case because the plaintiff had failed to introduce any evidence that the alleged defective warning had caused plaintiffs injury.
¶30 GM engineer Robert Lange testified that an audible warning of mis-shifts was feasible in the 1970s and could have been installed in GM vehicles from that time forward. Plaintiffs also provided the jury with GM engineer Roger McCarthy’s testimony in a similar case that a person would react with “surprise and shock” and “investigate” the first time he or she heard an audible warning or saw flashing lights triggered by a misshift, although that person might ignore such warnings if repeated multiple times. Plaintiffs’ expert witness, Dr. Mark Sanders, opined that an audible warning of a mis-shift would be “very effective.”
¶ 31 Reasonable persons could infer from this evidence that an audible warning system would have alerted Mrs. Golonka to a misshift before she walked behind the truck and dropped its tailgate, and that the warning would have caused her to take action to prevent the accident.
Masaki v. General Motors Corp.,
¶32 Plaintiffs also introduced evidence that GM could have issued better warnings in its owner’s manual, or by sending warning letters or on-product labels to customers. According to Dr. Sanders, a warning label about mis-shifts affixed to the visor or steering column, or a separate warning letter, “would have definitely increased the probability that [Mrs. Golonka] would have taken appropriate action.” This evidence supported a conclusion that a different or better written warning would have prevented Mrs. Golonka’s death.
¶ 33 Finally, Plaintiffs introduced evidence that Mrs. Golonka had read portions of the owner’s manual for the 1987 Sierra truck, had heeded the truck’s “service vehicle soon” light when activated, and had heeded safety warnings for other products. The jury could have reasonably inferred from this evidence that Mrs. Golonka was safety conscious and would have heeded a better warning about mis-shifts. GM argues that we should not consider this evidence because the trial court erred by denying a motion in limine to preclude it as inadmissible character evidence. Ariz. R. Evid. 404(a) (“Evidence of a person’s character or a trait of character is not admissible for the purpose of proving action in conformity therewith on a particular occasion____”). Plaintiffs countered at trial that the evidence demonstrated Mrs. Golonka’s habit of heeding safety warnings and was therefore admissible. Ariz. R. Evid. 406 (“Evidence of the habit of a person ... is relevant to prove that the conduct of the person ... on a particular occasion was in conformity with the habit____”). After
*586 argument on the motion, the court informed GM that a ruling would not be immediately forthcoming and that GM “should proceed as it deems appropriate” and could recall a witness after the ruling to elicit any testimony affected by the ruling. Regardless, GM chose to elicit testimony about Mrs. Golonka’s failure to heed warnings and did not object to Plaintiffs’ questions about Mrs. Golonka’s adherence to other warnings.
¶ 34 Eventually, the trial court denied GM’s motion
in limine,
ruling that GM had waived the issue by its conduct. Because the court had not ruled on the motion
in limine
at the time both parties elicited competing testimony about Mrs. Golonka’s treatment of safety warnings, the court did not abuse its discretion by denying the motion based on waiver.
5
See State v. Burton,
¶ 35 Plaintiffs introduced sufficient evidence of causation to submit the warnings claims to the jury. Consequently, the trial court did not err by denying GM’s motion for JMOL.
C. Jury instruction on heeding presumption
¶36 GM next argues that the trial court erred by instructing the jury on the so-called “heeding presumption.” We will reverse on this basis only if the instruction was both erroneous and prejudicial to GM’s substantial rights.
Gemstar Ltd. v. Ernst & Young,
¶ 37 The “heeding presumption” is a rebut-table presumption used in a strict liability information defect case to allow the fact-finder to presume that the person injured by product use would have heeded an adequate warning, if given.
Dole Food Co. v. N. Carolina Foam Indus., Inc.,
¶ 38 The trial court instructed the jury on the heeding presumption as follows:
Where a warning is given, a seller may reasonably assume that it will be read and heeded. If you find the warning is adequate, then your verdict must be for Defendant on this claim. However, if you find the warning to be inadequate, then you must start with the presumption that an adequate warning would have been read and heeded. In those circumstances, the Defendant then has the burden of proving that it is more probably true than not that an adequate warning would not have been read or would not have been heeded.
You may consider all the evidence presented in this case to make that determina *587 tion. If you find the Defendant has proved that an adequate warning would not have been read or heeded, then your verdict must be for Defendant on this claim. If you find that Defendant has not proved that an adequate warning would not have been read or heeded, then you may return a verdict for Plaintiff on this claim if you find that Plaintiff has proved the other elements of this claim.
GM contends the court erred in giving this instruction because (1) the heeding presumption is not utilized in Arizona, (2) even if the presumption is utilized, it is inapplicable in this case, and (3) the instruction incorrectly shifted the burden of persuasion to GM concerning causation. We address each contention in turn.
1. The heeding presumption in Arizona
¶ 39 In
Dole Food,
¶ 40 GM overlooks the fact, however, that courts have adopted the heeding presumption without reference to comment j.
See Coffman,
¶ 41 Strict tort liability stems in significant part from a public policy that seeks to achieve safety in the marketplace by providing a disincentive to manufacturers to place defective and unreasonably dangerous products into the stream of commerce.
Salt River Project Agric. Improvement and Power Dist. v. Westinghouse Elec. Corp.,
¶42 In light of the difficulty of demonstrating how an injured or deceased person would have reacted to a particular warning,
see swpra
¶37, manufacturers who issue products with inadequate safety warnings could escape any consequence, thereby decreasing the incentive for manufacturers to adequately warn consumers of dangers inherent in product use. By easing the burden of proving causation, “[t]he use of the heeding presumption provides a powerful incentive for manufacturers to abide by their duty to provide adequate warnings.”
Coffman,
¶ 43 Additionally, use of the heeding presumption is often procedurally desirable. Specifically, the presumption assists plaintiffs in proving causation in cases in which the injured person has either died or has become incapacitated, and evidence of how that person would have reacted to an adequate warning is therefore limited or unavailable.
General Motors Corp. v. Saenz ex rel. Saenz,
¶ 44 In summary, use of the heeding presumption in strict liability failure-to-warn eases furthers Arizona’s policy of protecting the public from defective and unreasonably dangerous products. The presumption is also procedurally desirable to ensure that legitimate claims of information defect are fairly addressed. For these reasons, the heeding presumption is viable in Arizona.
2. Applicability of heeding presumption in this case
¶45 GM next argues that even assuming the viability of the heeding presumption in Arizona, the trial court erred in instructing the jury on it because the presumption dissipated in the face of evidence supporting a finding that Mrs. Golonka would not have heeded an adequate warning about misshifts. GM relies on this court’s decision in
Sheehan v. Pima County,
which determined ‘that if the heeding presumption existed in that case, it “disappear[ed] entirely upon the introduction of any contradicting evidence” and the existence of the previously presumed fact must be determined exactly as if no presumption existed.
¶ 46 Plaintiffs do not address
Sheehan
in their answering brief,
8
but instead cite this court’s decision in
Dole Food Co. v. North Carolina Foam Ind., Inc.,
to support their contention that the heeding presumption permanently shifts the burden to the manufacturer to prove that the injured person would not have heeded an adequate warning. In
Dole Food,
the court explained that the effect of the heeding presumption in that case was “to take the case to the jury, even in the face of [the manufacturer’s] contrary evidence” that an adequate warning would not have been heeded.
*589 stated that “the presumption shifts the burden of proof to [the manufacturer], and it is up to the jury to determine whether the burden has been satisfied.” Id. The trial court relied on Dole Food in instructing the jury on the heeding presumption.
¶ 47 To resolve the conflict between Sheehan and Dole Food, we examine the operation of presumptions used in civil cases in Arizona. Thereafter, we decide how the heeding presumption operates and whether the court correctly instructed the jury on the presumption in this case.
¶48 In 1938, the Arizona Supreme Court adopted the “bursting bubble” theory of presumptions championed by Harvard Law Professor James B. Thayer.
See Seiler v. Whiting, 52
Ariz. 542, 547-48,
¶ 49 Although the supreme court has consistently applied the “bursting bubble” theory to its treatment of presumptions, 10 it has not differentiated between the types of presumptions that shift the burden of production from those that shift the burden of persuasion to the party opposing the presumption. See Joseph M. Livermore, et al., Arizona Practice, Law of Evidence § 301.4, at 50 (4th ed.2000) (noting that Arizona statutes and eases have created hundreds of evidentiary presumptions that either shift the burden of production or the burden of persuasion or have undetermined effects). Similarly, the Arizona Rules of Evidence, unlike their federal counterpart, 11 are silent on the subject. Thus, discerning the quantum of evidence *590 needed to burst a particular presumption bubble can be problematic. See Alexander L. Broadfoot, Presumptions Under Arizona Law: Divining the Standards, 35 Ariz. L.Rev. 1073, 1076-77 (1993) (discussing the difficulties in perceiving the burden-shifting effects of presumptions).
¶ 50 Arizona courts generally hold that a presumption is a procedural device that shifts the burden of producing contrary evidence to the party opposing the presumed fact but leaves the burden of persuasion on the proponent of the evidence.
Seiler,
¶ 51 Following the general rule, we agree with
Sheehan
that the heeding presumption shifts the burden of production rather than the burden of persuasion.
¶ 52 Based on the foregoing, the heeding presumption serves to shift the burden of production to the manufacturer. The manufacturer meets this burden by introducing evidence that would permit reasonable minds to conclude that the injured party would not have heeded an adequate warning.
See Helton v. Indus. Comm’n,
¶ 53 GM introduced competent evidence to rebut the heeding presumption. The owner’s manual for Mrs. Golonka’s truck cautioned that before the driver leaves the vehicle, “to reduce the risk of personal injury as a result of vehicle movement,” the driver should apply the parking brake, shift to park, shut off the engine, and remove the key. Despite this warning, Mrs. Golonka apparently did not set the parking brake, turn off the engine, or remove the key immediately prior to the accident. Mrs. Golonka also apparently ignored a buzzer that activated when she opened her door with the key still in the ignition. According to expert testimony elicited by GM, had Mrs. Golonka followed these steps, she would have prevented the accident.
¶54 Evidence that Mrs. Golonka ignored safety warnings that related to the accident would have allowed reasonable minds to conclude that she would have similarly ignored adequate warnings about misshifts.
See Gosewisch,
¶ 55 Although we do not lightly overturn a jury’s verdict, we are compelled to do so here because the erroneous jury instruction creates substantial doubt that the jurors were properly guided in their deliberations.
Gemstar,
¶ 56 In light of our decision, we need not address GM’s additional contention that a new trial is required because the jury’s comparative fault allocations reflect confused verdicts. Additionally, because different evidence may be adduced in a re-trial limited to the warnings-related claims, we do not address GM’s contention that the jury’s award of punitive damages was unwarranted.
See Progressive Specialty Ins. Co. v. Farmers Ins. Co. of Arizona,
D. Other issues that may arise on remand
1. Ronald Elwell’s testimony
¶57 GM argues that the trial court erred by allowing former GM mechanical engineer Ronald Elwell to testify that GM had a policy in the 1980s to spend no more money on safety issues than required by applicable federal standards. Elwell also related that GM’s reaction to a vehicle defect depended on “[t]he frequency of the defective performance times the consequences, which is cost to the American public, either in injuries or death.” According to GM, the court should have precluded this testimony as irrelevant, lacking in foundation, and as improper character evidence.
¶ 58 After conducting an evidentiary hearing outside the presence of the jury, the trial
*592
court ruled that the challenged aspect of Elwell’s testimony was at least relevant to the claim for punitive damages and therefore admissible. The court additionally rejected GM’s foundation argument by finding that Elwell had personal knowledge of the alleged GM policies. The court did not abuse its discretion by making these rulings.
Selby,
¶ 59 According to Elwell, GM’s minimal spending policy was irresponsible and hindered engineers’ efforts to make GM vehicles as safe as.possible. This evidence, coupled with evidence suggesting that GM knew about the mis-shift problem in the 1980s but ignored it, increases the probability that GM “consciously disregard[ed] the unjustifiabl[e] substantial risk of significant harm” to others, thereby justifying an award of punitive damages.
Thompson v. Better Bilt Aluminum Products Co.,
¶ 60 The record also reflects that Elwell had personal knowledge of the GM policies at issue. Elwell testified that he worked in GM’s Engineering Analysis Group, which investigated legal claims asserted against GM and knew GM’s safety policies and procedures as part of his job. Elwell’s superior informed him of the contested minimal-spending policy in the early 1980s and, according to Elwell, this policy was widely communicated to GM engineers. Additionally, Elwell stated he used GM’s alleged defect-assessment policy when reporting fuel system problems to upper management. Based on this testimony, the court did not err by finding that Elwell had sufficient personal knowledge of GM’s policies to testify about them. See Ariz. R. Evid. 602.
¶ 61 Finally, evidence of GM’s policies in effect in the 1980s is not prohibited character evidence under Rule 404(a), Arizona Rules of Evidence. GM asserts that Elwell had no knowledge about transmission design and related warnings, and evidence of the contested policies was therefore necessarily confined to the areas of Elwell’s job responsibilities. For this reason, GM contends that evidence of the policies was impermissibly used to show that GM acted in conformity with this “corporate mentality” when addressing the mis-shift problem. But Elwell did not state that GM’s policies were limited to a specific GM product division. Rather, he related that he needed to know GM’s general safety policies and procedures. We therefore reject GM’s contention.
2. State-of-the-art defense
¶ 62 GM also argues that the trial court erred by refusing to give a state-of-the-art defense jury instruction relating to written warnings. Section 12-683, A.R.S., provides, in pertinent part, as follows:
In any product liability action, a defendant shall not be liable if the defendant proves that any of the following apply:
1. The defect in the product is alleged to result from inadequate design or fabrication, and if the plans or designs for the product or the methods and techniques of manufacturing, inspecting, testing and labeling the product conformed with the state of the art at the time the product was first sold by the defendant.
“ ‘State of the art’ means the technical, mechanical and scientific knowledge of manufacturing, designing, testing or labeling the same or similar products which was in existence and reasonably feasible for use at the time of manufacture.” A.R.S. § 12-681(8) (Supp.2002).
¶ 63 The trial court found that § 12-683(1) applied to allow GM to defend against the failure-to-warn/information defect claims by arguing that its active warning system (i.e., horn, flashing lights, buzzers) and on-product labeling were state of the art. However, the court ruled sufficient evidence did not support a state-of-the-art defense regarding written warnings. Consequently, although the court gave a state-of-the-art instruction concerning the active warning system and on-product labeling, the court told the jury to “not consider the state-of-the-art defense as to any claim whether product liability or negligence[ ] based on the alleged failure to provide adequate written warnings (other than on-prod *593 uct labels).” GM contends the court erred by refusing to extend the state-of-the-art defense instruction to written warnings because sufficient evidence supported such an instruction.
¶ 64 A trial court must instruct the jury on all legal theories supported by the evidence.
Gemstar,
CONCLUSION
¶ 65 For the foregoing reasons, we hold that the jury necessarily found GM at fault only for negligent failure to warn and strict liability information defect. The trial court correctly denied GM’s motion for JMOL on these claims. The court also properly denied GM’s request for a state-of-the-art defense jury instruction relating to the written warnings. However, although the court properly recognized the viability of the heeding presumption in Arizona, the court improperly instructed the jury on this presumption. Because this error prejudiced GM’s substantial rights, we reverse and remand for a new trial on Plaintiffs’ claims for negligent failure to warn and strict liability information defect.
Notes
. Plaintiffs argue that GM waived this argument by failing to seek either a special verdict or a jury interrogatory that would have revealed the basis for the negligence verdict. We disagree. GM is not challenging the verdicts as defective or ambiguous.
Cf. Mong Ming Club v. Tang,
. The supreme court has approved the following non-exhaustive list of factors devised by leading commentator Dean Wade:
"(1) [t]he usefulness and desirability of the product,
(2) the availability of other and safer products to meet the same need,
is) the likelihood of injury and its probable seriousness,
(4) the obviousness of the danger,
(5) common knowledge and normal public expectation of the danger (particularly for established products),
(6) the avoidability of injury by care in use of the product (including the effect of instructions or warnings), and
(7) the ability to eliminate the danger without seriously impairing the usefulness of the product or making it unduly expensive.”
Dart,
. In light of the court’s instruction, the jury in this case also employed the consumer expectation test to reject Plaintiffs’ strict liability design claim. But because the jury also employed the risk/benefit analysis to reject the strict liability design claim, we need not decide whether a jury could consistently reject such a claim using the consumer expectation test, yet accept a factually identical negligent design claim. We note, however, that courts from other jurisdictions and commentators have opined that a jury cannot under any circumstances consistently reject a strict liability design claim and accept a negligent design claim.
See, e.g., Tipton v. Michelin Tire Co.,
. Plaintiffs additionally contend that the court properly denied GM's motion for JMOL because the jury was entitled to presume that Mrs. Golonka would have heeded a proper warning. As explained, infra ¶¶ 52-54, Plaintiffs lost the benefit of this presumption once GM presented credible evidence controverting the presumed fact. Therefore, we consider only the presented evidence to decide whether the trial court properly denied the motion for JMOL.
. The trial court’s denial of the motion
in limine
was additionally warranted because GM had placed at issue Mrs. Golonka’s propensity for heeding safety warnings, presumably in an attempt to rebut the heeding presumption.
See infra
¶¶ 37, 39-44 for a discussion of the heeding presumption. GM could not simultaneously rebut the heeding presumption by introducing evidence that Mrs. Golonka had ignored safety warnings and then object to Plaintiffs’ countervailing evidence that Mrs. Golonka had heeded safety warnings.
Bell v. State,
. Comment j provides: "Where a warning is given, the seller may reasonably assume that it will be read and heeded; and a product bearing such a warning, which is safe for use if it is followed, is not in defective condition, nor is it unreasonably dangerous.” As noted by the
Dole Food
court, although comment j concerns what a seller may presume, courts have held that the presumption "works both ways” and may be used to show that an injured party would have heeded an adequate warning.
.
See Coffman,
. During oral argument, Plaintiffs argued that the language from
Sheehan
relied upon by GM is dicta, which we should ignore. We disagree with Plaintiffs’ characterization. The
Sheehan
court’s description of the effect of the presumption was essential to the determination of the case and was therefore not dicta.
See Clark Equip. Co. v. Arizona Prop. & Cas. Ins. Guar. Fund,
. By deciding that the presumption dissipates when the opponent has met "the burden of production or proof imposed by the presumption,” the
Grilz
court adopted a somewhat modified approach to the "bursting bubble” theory, which typically serves to shift only the burden of production. 2 J.W. Strong,
McCormick on Evidence,
§ 344(A) (4th ed.1992) [hereinafter
McCormick on Evidence
]. Thus, if a presumption shifts the burden of persuasion, in order to destroy that presumption, its opponent must necessarily introduce a sufficient quantum of evidence contradicting the presumed fact to persuade the court of the non-existence of that fact.
See v. Grilz,
. The supreme court has reaffirmed use of the “bursting bubble” theory for both statutory and non-statutoiy presumptions.
Grilz,
. Federal Rule of Evidence 301 provides as follows:
In all civil actions and proceedings not otherwise provided for by Act of Congress or by these rules, a presumption imposes on the party against whom it is directed the burden of going forward with evidence to rebut or meet the presumption, but does not shift to such party the burden of proof in the sense of the risk of nonpersuasion, which remains throughout the trial upon the party on whom it was originally cast.
