Mark Kedrowski, Appellant, vs. Lycoming Engines, a division of AVCO Corporation, Respondent.
A17-0538
STATE OF MINNESOTA IN SUPREME COURT
September 11, 2019
Anderson, J.
Court of Appeals. Filed: September 11, 2019. Office of Appellate Courts.
Thomas W. Fuller, Cortney S. LeNeave, Hunegs, LeNeave & Kvas, P.A., Wayzata, Minnesota; and
Stephen P. Watters, Watters Law Office, Minnetonka, Minnesota, for appellant.
Steven J. Wells, Timothy J. Droske, Andrew B. Brantingham, Dorsey & Whitney LLP, Minneapolis, Minnesota; and
Daniel A. Haws, John Paul J. Gatto, HKM, P.A., Saint Paul, Minnesota, for respondent.
Michael L. Weiner, Yaeger & Weiner, PLC, Minneapolis, Minnesota, for amicus curiae Minnesota Association for Justice.
- Because the district court abused its discretion by excluding the entire causation opinion of an expert witness when only one ground for the expert‘s causation opinion lacked foundational reliability, judgment as a matter of law was error.
- The erroneous admission of the unreliable part of the expert‘s opinion warrants a new trial on liability.
Reversed and remanded.
O P I N I O N
ANDERSON, Justice.
This litigation arises from the crash of a single-engine airplane, which resulted in seriоus injuries to appellant Mark Kedrowski, the pilot of the airplane. According to Kedrowski‘s expert, a defective fuel pump manufactured by respondent Lycoming Engines caused the airplane to lose power and crash. After the jury returned a $27.7 million verdict for Kedrowski, the district court ruled that the opinion of Kedrowski‘s sole expert on causation lacked foundational reliability under
On September 3, 2010, Kedrowski crashed his single-engine airplane shortly after takeoff from the Lake Elmo Airport, sustaining serious injuries. Kedrowski told a first responder that “he lost power and was trying to get back to the airport” when the crash occurred. Kedrowski now has no memory of the accident or what happened to cause the airplane to crash.
Kedrowski brought an action against both Lycoming and Kelly Aerospace Power Systems, Inc., which manufactured the fuel pump of the airplane engine as part of a joint enterprise.1 As relevant here, Kedrowski alleged that Lycoming manufactured the engine, including the fuel delivery system, “in a defective condition that was unreasonably dangerous to users and consumers.” Kedrowski alleged that, as a result, his airplane lost power and crashed and that he suffered severe personal injuries. Lycoming asserted a pilot-error defense in its answer.
Kedrowski retained expert Donаld Sommer to investigate the crash. Sommer holds a degree in mechanical engineering and is a registered professional engineer. He is licensed by the Federal Aviation Administration as an airline transport and commercial pilot and has been authorized to instruct student pilots. He has over 16,000 hours of flight experience and specializes in aircraft accident reconstruction.
Sommer was of the opinion that the diaphragm-style Lycoming LW–15473 fuel pump in Kedrowski‘s airplane had manufacturing defects and that those defects caused
[A] fuel pump is the heart of an airplanе. It works very much like a heart. It has valves, and the airplane depends on its function. When the heart goes into a reduced performance or when the heart starts leaking or when the heart has weak muscles, the problem is that the engine loses power. The airplane loses power. In a single-engine airplane, that means that the airplane is going to come down to the Earth, and that‘s what happened in this case.
Sommer reached this opinion after a multifaceted investigation. Sommer reconstructed Kedrowski‘s flight path, reviewed the airplane‘s maintenance history and operating manuals, reviewed Lycoming engineering documents, and analyzed the plane‘s propeller and engine components. Sommer also evaluated “human factors” and interviewed Kedrowski.
Two parts of Sommer‘s investigation corroborated Kedrowski‘s statement to the first responder that his airplane lost pоwer before the crash. First, Sommer inspected the airplane‘s propeller, which had not been severely damaged in the accident sequence. According to Sommer, the propeller was “virtually pristine.” Sommer testified that “you will never find a blade like this on an engine that‘s making power.” Sommer testified that the propeller analysis showed that the engine was producing “low power at impact.”
Second, Sommer testified that “the engine was pretty much in one piece” and had not “been completely damaged by the accident sequence,” which allowed Sommer and his investigation team to install the engine on a dynamometer. As Sommer described, a
To determine the cause of the power loss, Sommer “analyzed every part and component on the engine.” He tested the fuel servo, which “operated fine.” He also tested the engine‘s two ignition systems, which “both worked, and they both ran the engine.”
Sommer learned something from his interview with Kedrowski that “really piqued” his interest in the fuel pump. Kedrowski told Sommer of occasions where he would engage a separate boost pump when starting the plane, “which is normal.” But when Kedrowski would turn off the boost pump, the engine would die. Sommer testified that these experiences were “significant” because they “mеan[t] that the engine-driven pump has a problem“:
[I]f an engine will run only with the boost pump on and stops running when the boost pump is off and continued to run when the boost pump was turned back on, that‘s pretty much . . . a no brainer to me that the engine-driven pump was not providing for the needs of the engine.
That the engine “quit when the boost pump was removed” revealed to Sommer that “the fuel pump had a history of not providing for the needs of the engine.” Sommer testified
Sommer tested the pump on a flow bench. This testing became the focus of the parties’ arguments on appeal. A flow bench is a “specialized test fixture” that is used to measure pump performance. A flow-bench test requires three parameters: the revolutions per minute (rpm) of the engine attached to the pump, the pounds per squarе inch (psi) of pressure output by the pump, and the pounds per hour (pph) of fuel flowing through the pump. These three parameters are interrelated, as Sommer testified:
[I]f you lower the flow coming out of the pump, in other words, you restrict it, you close down a valve, or in the case of an engine, the fuel injection system closes down. If you lower the flow, the pressure will go up. If you lower the pressure, the flow will go down. So they‘re interrelated, and you can control one through the other.
Sommer‘s investigation team “obtained some test parameters for the pump, flows and pressures,” and “operated the pump close to those test parameters in order to determine whether or not it met the parameters.” Sommer obtained the parameters from Aero Accessories, which Sommer described as “a shop that‘s approved to manufacture Lycoming fuel pumps.” Sommer had an employee call an Aero Accessories employee, who provided specifications in an email.
In part, the Aero Accessories specifications stated that the pump should produce 271 pph of flow at 1800 rpm and 24 to 30 psi. Sommer‘s flow-bench test of the accident pump at those parameters showed that it produced only 48 pph of fuel flow at 1800 rpm and 25 psi. Sommer‘s flow-bench testing showed him that “the fuel pump wasn‘t coming anywhere near the specifications we received.” Specifically, the pump “didn‘t make the
Sommer later disassembled the pump. He testified that he “found some issues.” When testing the pump‘s valve for air leaks, Sommer discovered “that we had potentially a very serious set of leaks in both the inlet and outlet check valves.” Sommer also found that a “valve wasn‘t installed square in the hole” and that manufacturing problems “created a direct leakage path around the check valve for the inlet check valve.”2
Sommer‘s investigation extended beyond the fuel pump. Sommer and his team “dis[as]sembled the engine completely, took it apart pretty much every nut and bolt and looked at all the stuff that you can look at on an engine.” Sommer, despite having never worked on a diaphragm-style pump before, had performed “hundreds and hundreds, probably, close to a thousand” aircraft engine teardowns, and was “looking for anything that could explain [the] loss in horsepower.” But the pistons, valves, cylinders, camshaft, crankshaft, connecting rods, and “all the internal components of the engine” appeared normal. Sommer testified that, “from the standpoint of the major mechanical components inside the engine, there was nothing there that was suspicious.” Sommer believed that this
I went through everything in that engine that could possibly have made [the engine] lose power. The fuel system, the magneto system, the spark plugs, the fuel injection servo, the boost pump—every component that could possibly have caused this engine to fail was analyzed, and there was only one that was found with defects, and that‘s the engine-driven fuel pump.
“[T]he only conclusion that makes sense, after almost four years of researching this,” Sommer testified, “is that the fuel pump caused the engine . . . to reduce itself in power.”
Additionally, Sommer tested the pump оn a different airplane. After the fuel pump was installed, “they couldn‘t get the airplane started.” Sommer testified that “the only thing different about this configuration was the accident fuel pump, and the engine wouldn‘t start without an excessive amount of cranking. So something was wrong, and the only difference was the pump.”
Lycoming challenged Sommer‘s opinion at every stage. In a motion in limine, Lycoming argued that Sommer should be precluded from offering an expert opinion because his report lacked reliability under
At trial, Lycoming pressed Sommer on his selection of flow-bench-test parameters. Lycoming insisted that its design specifications for the pump should have been used. The design specifications identified two key sets of flow-bench-test parameters: a “minimum capacity test,” which called for the pump flow to be tested at 2 psi, and a “shut off pressure”
Sommer disavowed Lycoming‘s design specifications, testifying that “the pump design drawing specification pressures have no relation to running an engine.”3
Someone who knows fuel pumps would know that no engine that‘s ever been built by any engine manufacturer with a fuel injection system will run on [2] psi. And if you‘re doing an accident investigation, it‘s folly to try to pick one data point out of the sky that has nothing to do with the engine and say: Here we go, let‘s run this spec.
According to Sommer, the engine required a minimum fuel pressure of 18 psi and a maximum of 26 psi. Sommer iterated that Lycoming‘s design specifications for the pump are “two data points which aren‘t relevant” to engine operation. Two psi “is a non sеquitur,” Sommer testified, because it “doesn‘t help me determine why the engine ceased producing power.” The shutoff specification was irrelevant because “shutoff means no fuel flow,” but “[a]n engine cannot operate without fuel.” Sommer explained that he did not test to Lycoming‘s design parameters, stating, “I‘m an accident reconstructionist. I test the fuel pump to see if the fuel pump can cause an accident as it did in this case, and, therefore, I‘m going to run the pump at parameters that are closer to what an engine seats.” Sommer reiterated, “The 2 psi specifications did not matter because 2 psi does not run an
The district court overruled Lycoming‘s foundation objection at trial, reasoning that “[i]t goes to weight.” After Kedrowski rested, Lycoming moved for judgment as a matter of law. See
Before ruling, the district court noted that the motion for judgment as a matter of law “is complicated and challenging.” “With regard to causation,” the court stated, it is a “very close question.” The court concluded that a jury “could reasonably infer that other possible causes of engine failure or loss of power due to the mechanical operation of the engine were ruled out” and that “the fuel pump did not meet specifications applicable to it.” The controversy over whether Sommer misunderstood the use of pump parameters was “subject to debate“—an “inconsistenc[y] . . . for the jury to resolve and . . . not for [the court] to resolve as a matter of law.” The court stated that “causation issues are generally matters of fact for the jury, and only in the clearest of cases does the question become one of law, and this is not so clear a case. In fact, it‘s a close case.”
The case was submitted to the jury. The jury returned a special verdict. Although the jury did not find that the Lycoming fuel pump was defective in design, it did find that the Lycoming pump was unreasonably dangerous because of a manufacturing defect and that the manufacturing defect was a direct cause of the injuries sustained by Kedrowski.
Lycoming renewed its motion for judgment as a matter of law. See
On this occasion, in a thorough and exhaustive order, the district court granted Lycoming‘s motion for judgment as a matter of law. Although the district court described the evidence as “more than adequate” to support the jury‘s finding of a manufacturing defect, “[t]he mere existence of defects in the LW-15473 fuel pump does not prove that those defects caused plaintiff‘s crash.” The court stated that Kedrowski needed “an admissible expert opinion that the subject fuel pump was, more likely than not, a substantial contributing factor in causing the crash.” Seе Gross v. Victoria Station Farms, Inc., 578 N.W.2d 757, 762 (Minn. 1998) (“Expert opinion is required to prove causation if the issue is outside the realm of common knowledge.“). The court found that Sommer was the sole causation expert but that his opinion on causation lacked foundational reliability. Without Sommer‘s causation opinion, Kedrowski‘s claims against Lycoming failed, and Lycoming was entitled to judgment as a matter of law notwithstanding the jury‘s verdict.
Kedrowski appealed the grant of judgment as a matter of law to Lycoming. Lycoming cross-appealed, arguing that, as relevant here, in the event that the judgment as a matter of law in favor of Lycoming was reversed, a new trial should be granted on the issue of damages because the district court erroneously analyzed the damages award under
ANALYSIS
The issue we consider here is whether the grant of judgment as a matter of law to Lycoming was error, which requires that we review the district court‘s posttrial exclusion of Sommer‘s causation opinion. Because we conclude that the evidentiary ruling was an abuse of discretion and, consequently, that judgment as a matter of law was error, we also consider whether a new trial should be granted to Lycoming.
I.
On review of the grant of a motion for judgment as a matter of law, we make an “independent determination” of the sufficiency of the evidence. Jerry‘s Enters., Inc. v. Larkin, Hoffman, Daly & Lindgren, Ltd., 711 N.W.2d 811, 816 (Minn. 2006). Judgment
A.
The standard for judgment as a matter of law requires that we take account of all of the evidence Lamb, 333 N.W.2d at 855. We first address whether a court may reconsider rulings on the admissibility of evidence when ruling on a posttrial motion for judgment as a matter of law.
Traditionally, we have said that evidentiary rulings made during trial are not to be revisited on a motion for judgment as a matter of law. See Coble v. Lacey, 90 N.W.2d 314, 322 (Minn. 1958) (stating that “judgment notwithstanding the verdict will never be granted for errors in either law or procedure committed at the trial“); Eichler v. Equity Farms, Inc., 259 N.W. 545, 545 (Minn. 1935) (per curiam) (stating that in a motion for judgment notwithstanding the verdict, “[o]bjections cannot be raised . . . to rulings on the trial” (citation omitted) (internal quotation marks omitted)); Bosch v. Chi., Milwaukee & St. Paul Ry. Co., 155 N.W. 202, 203 (Minn. 1915) (“[J]udgment notwithstanding the verdict will
More recently, we seem to have been less categorical about this concept. See Reinhardt v. Colton, 337 N.W.2d 88, 92 n.1 (Minn. 1983) (noting that the standard for judgment as a matter of law “suggests that the stage of the proceeding at which a motion for [judgment notwithstanding the verdict] is brought is an inappropriate time at which to effectuate a determination regarding the admissibility of evidence“); Rochester Wood Specialties, Inc. v. Rions, 176 N.W.2d 548, 552 (Minn. 1970) (agreeing with the district court that there was insufficient evidence of negligence at trial, while also stating that “[t]he expert opinions offered by plaintiff were not consistent and should not have been received“). Reinhardt and Rochester Wood neither referenced, nor repudiated, nor affirmed the Nw. Marble line of cases.4
Here, on the posttrial motion for judgment as a matter of law made by Lycoming, the district court—before considering the sufficiency of the evidence—first determined that Sommer‘s causation opinion should have been excluded. Referencing Coble, amicus Minnesota Association for Justice posits that, in so doing, the district court erred. The parties rely on our more recent decisions: Kedrowski argues that the Reinhardt footnote
We need not resolve the issue of which rule applies to the current dispute. Solely for the purpose of this appeal, we will assume without deciding that it was not error for the district court to revisit and reverse its prior evidentiary ruling when deciding the motion for judgment as a matter of law because, regardless of which line of cases controls, the district court‘s evidentiary ruling was itself erroneous.
B.
Kedrowski argues that the district court abused its discretion by excluding all of Sommer‘s causation opinion on foundational reliability grounds. We conclude that the district court did not abuse its discretion by finding that Sommer‘s flow-bench testing was foundationally unreliable but did abuse its discretion by excluding Sommer‘s entire causation opinion.
Expert opinion testimony “must have foundational reliability.”
Beyond theory and methodology, “expert familiarity with the facts of a case is an essentiаl element of reliability.” Peter B. Knapp, The Other Shoe Drops: Minnesota Rejects Daubert, 27 Wm. Mitchell L. Rev. 997, 1015 (2000); cf. Hudson v. Trillium Staffing, 896 N.W.2d 536, 540 (Minn. 2017) (“It is well settled that expert opinions must have an adequate factual foundation to be admissible.“). When determining whether expert testimony has a reliable factual foundation, the question is whether “[t]he facts upon which an expert relies for an opinion [are] supported by the evidence.” Gianotti v. Indep. Sch. Dist. 152, 889 N.W.2d 796, 801–02 (Minn. 2017). The factual foundation of an expert‘s opinion is inadequate if “(1) the opinion does not include the facts and/or data upon which the expert relied in forming the opinion, (2) it does not explain the basis for the opinion, or (3) the facts assumed by the expert in rendering an opinion are not supported by the evidence.” Mattick v. Hy-Vee Foods Stores, 898 N.W.2d 616, 621 (Minn. 2017) (citation omitted) (internal quotation marks omitted).
The district court gave three independent rationales for excluding Sommer‘s causation opinion: (1) Sommer‘s flow-bench testing, (2) Sommer‘s failure to account for the fact that Kedrowski flew for over 300 hours before the crash, and (3) Sommer‘s failure to acсount for his statement that Kedrowski‘s plane could still fly with a 40-percent power loss. We address each in turn, reviewing for an abuse of discretion. Doe, 817 N.W.2d at 164.
First, the district court found that Sommer conducted the flow-bench test “using an inherently unreliable methodology.” The court looked to Sommer‘s testimony that his flow-bench testing showed him that the pump was unable to produce “design flow and pressure.” The court observed that Sommer used parameters obtained from a third-party parts vendor to conclude that the pump did not perform to specifications. But the district court found that those parameters came “from an unknown document that was later definitively proven not to be what Mr. Sommer assumed he needed to validate his theory“—they were neither Lycoming‘s design parameters nor represented the fuel needs of Kedrowski‘s engine. Because it was “apparent” to the court that the “scientific underpinnings” of Sommer‘s causation opinion depended on the validity of his flow-bench testing, the court found that Sommer‘s causation opinion should have been excluded.
We have little trouble affirming the district court‘s detailed and thorough analysis finding that Sommer‘s flow-bench testing lacked foundational reliability.5 The record shows that Sommer could not consistently explain why he ran the flow-bench test as he did. Sommer first explained his opinion about the pump, derived from the flow-bench testing, specifically in terms of design parameters: “The flow bench testing showed me
But when confronted with the parameters from Lycoming‘s design drawing, Sommer changed course. Sommer was no longer concerned with the pump‘s “design,” but rather with the pump‘s effect on engine performance. “I‘m not concerned with the design drawing specifications,” he testified. “I‘m concerned with what the pump was capable of doing.” Testing to Lycoming parameters “is not something that we did in this case because that will not run an engine.” The 2 psi specification from Lycoming‘s design drawing was, in Sommer‘s words, not worth testing and was “a non-sequitur” because an engine could not run at that pressure. The engine required 18 psi.
Neither of Sommer‘s explanations correspond to the parameters that Sommer actually employed in the testing process. Although Kedrowski does not concede that the parameters Sommer tested were meaningless, he does not argue that the parameters Sommer obtained in an email from a third-party parts vendor are Lycoming‘s design parameters. The third-party parameters and the Lycoming parameters are different.
Moreover, nothing in the record shows that the third-party parameters were representative of the fuel needs of the engine in Kedrowski‘s aircraft. This is evident for two reasons. First, Sommer tested parameters that would not run the еngine. One of Sommer‘s flow-bench parameters was 5 to 8 psi. By Sommer‘s own logic, this parameter, like the 2 psi parameter from Lycoming‘s design specifications, could not in any way relate to engine performance because the engine required fuel flow of 18 psi. In Sommer‘s words, testing at a data point like 5 to 8 psi was “folly” because, at that level, the engine would
An expert should be able to explain test methodology consistently. If the expert cannot do so, the district court does not abuse its discretion by excluding evidence of that testing under
2.
That said, because the district court‘s leap from this sound result to the conclusion that Sommer‘s entire causation opinion should be stricken is puzzling, we next address whether the court‘s exclusion was overbroad. Although district courts have wide discretion in ruling on expert opinion testimony, that discretion must be “exercised favorably to any honest course capable of eliciting relevant truth.” Lestico v. Kuehner, 283 N.W. 122, 126 (Minn. 1938). “Where a portion of the proffered expert testimony is reliable, wholesale exclusion can constitute an abuse of discretion.” Sorrels v. NCL (Bahamas) Ltd., 796 F.3d 1275, 1281 (11th Cir. 2015).
Here, the district court excluded Sommer‘s entire causation opinion because it was “apparent” that the “scientific underpinnings” of Sommer‘s opinion depended entirely on the validity of the flow-bench testing. But Sommer based his causation opinion on more
In addition to the differential analysis, Sommer also grounded his opinion on Kedrowski‘s personal experiences with the boost pump. Kedrowski told Sommer about several occasions where his engine would quit when he turned off the boost pump. To Sommer, these experiences indicated that “the fuel pump ha[d] a history of not providing for the needs of the engine.” Kedrowski‘s boost-pump experiences showed Sommer that “the engine was not capable of running on that pump.” Sommer, whose expertise on the subject matter is not in dispute, testified that this conclusion was “a no brainer.”
We are not persuaded by Lycoming‘s argument that Sommer‘s differential analysis is similar to the differential diagnoses excluded in Goeb v. Tharaldson, 615 N.W.2d 800, 815–16 (Minn. 2000). In Goeb, the plaintiffs offered the testimony of two doctors to prove that a chemical manufactured by one of the defendants had caused their illnesses. See id. at 805. The district court excluded the testimony of both doctors because it found that their methodology was unreliable. See id. at 803. We affirmed, relying in part on the fact that, although both doctors claimed that they conducted a differential diagnosis, neither had reviewed the postexposure medical records of the plaintiffs. See id. at 815–16.
Lycoming also faults Sommer‘s differential analysis because it does not quantify the impact of the pump‘s defects on its fuel flow. But Lycoming cites no authority that all foundationally reliable expert causation testimony must be quantified. Although an opinion “clothed in the garb of mathematical accuracy,” Storbakken v. Soderberg, 75 N.W.2d 496, 501 (Minn. 1956), may be more persuasive, persuasiveness is not the sole measure of admissibility.
In sum, we cannot see how the deficiencies in Sommer‘s flow-bench testing tainted Sommer‘s investigation as a whole. Sommer‘s differential analysis and interpretation of Kedrowski‘s boost-pump experiences independently support his opinion that the defective
3.
We turn then to the district court‘s next rationale for excluding Sommer‘s causation opinion in its entirety. The court reasoned that Sommer‘s causation opinion should be excluded becаuse “Sommer offered no scientific basis to explain how plaintiff‘s aircraft ever got off the ground once the subject fuel pump was installed much less explain how it could fly for 312 hours before suddenly crashing.” The court described “the undisputed fact” (in apparent disregard of Sommer‘s interpretation of Kedrowski‘s boost-pump experiences) that the pump “supplied fuel to plaintiff‘s aircraft engine for 312 hours without any reported problems on take-off, during climb, or in the air.” The court also relied on the absence of testimony that the pump‘s defects “interfere[d] with engine operation on a variable basis.” The district court thus found that Sommer‘s causation opinion lacked “non-speculative foundational support.”
Notably, the district court did not fault Sommer for his reliance on his differential analysis. The court did not find that Sommer‘s total teardown and inspection of the engine, which discovered no defective parts except the Lycoming pump, was merely “speculation or conjecture.” See Gianotti, 889 N.W.2d at 802. Nor did the court state that Sommer‘s differential analysis lacked factual foundation for the other reasons described in Mattick, 898 N.W.2d at 621. Although the court called Sommer‘s interpretation of Kedrowski‘s boost-pump experiences “pure speculation” (because the court could identify other causes
Rather than addressing the actual grounds for Sommer‘s opinion, the district court faulted it for its perceived factual gaps. Essentially, the court excluded Sommer‘s opinion because of Sommer‘s perceived failure to account for the fact that Kedrowski‘s plane flew 312 hours before the crash. Kedrowski argues that this perceived gap in Sommer‘s testimony is an issue for the jury because it goes to Sommer‘s credibility, not his opinion‘s admissibility. We agree.
“[A]lleged deficiencies in [an expert‘s] factual basis go more to the weight of the expert‘s opinion than to its admissibility.” Bohach v. Thompson, 239 N.W.2d 764, 767 (Minn. 1976); see also LeMieux v. Bishop, 209 N.W.2d 379, 385 (Minn. 1973) (“[A]ny error in calculations or in the assumption of facts or data upon which the opinion was based goes to the weight of the testimony, not to its admissibility.“). Although the district court‘s observations may have some merit, and the еvidence supporting Sommer‘s claims is hardly overwhelming, Sommer‘s testimony is properly the subject of a detailed cross-examination and argument to the jury, rather than a foundational-reliability determination under
In concluding that Sommer‘s alleged failure to account for the fact that Kedrowski flew 312 hours before the crash is a question of weight, not of foundational reliability, we are mindful of “the line of distinction which separates the legitimate province of the [judge] from that of the [jury],” Hicks v. Stone, 13 Minn. 434, 437 (1868), which is that “the role of resolving disputed facts belongs to the jury, not the court,” Leiendecker v. Asian Women United of Minn., 895 N.W.2d 623, 635 (Minn. 2017); see also In re Sperl‘s Estate, 103 N.W. 502, 505 (Minn. 1905) (” ‘The cardinal maxim of our law, “Ad questiones facti non respondent judices,” is not to be lightly violated. Every attempt to do so simply introduces confusion and uncertainty.’ ” (citation omitted)); 1 Edward Coke, The First Part of the Institutes of the Laws of England, or, a Commentary upon Littlеton 155b (Francis Hargrave et al., eds., 1st Am. ed. 1812) (“ad questionem facli non respondent judices,” the principle that judges do not answer facts when a jury can do so). We hold that the district court abused its discretion by excluding Sommer‘s causation opinion based on a lack of factual foundation when the opinion also presented nonspeculative grounds, including Sommer‘s differential analysis and interpretation of past failures of the pump.
4.
The district court‘s last rationale fails for similar reasons. The district court noted that Sommer‘s “dynamometer testing established ‘around’ a 40% horsepower loss.” A 40-percent horsepower loss meant that the engine would operate with about
The fact that Kedrowski‘s airplane could remain aloft with the 40-percent power loss that Sommer attributed to the defective fuel pump is not itself fatal to Kedrowski‘s case. See Osborne v. Twin Town Bowl, Inc., 749 N.W.2d 367, 372 (Minn. 2008) (explaining that Minnesota recognizes substantial-factor causation rather than but-for causation). Sommer‘s alleged failure to reconcile his general statement that the plane was capable of flight with his specific causation opinion, which was based on his differential analysis and interpretation of Kedrowski‘s past failures of the pump, also goes to weight rather than admissibility, for the reasons set out earlier. We therefore hold that the exclusion of Sommer‘s сausation opinion on this basis also was an abuse of discretion.
C.
In sum, we conclude that the flaws in Sommer‘s flow-bench testing are not sufficient to exclude Sommer‘s ultimate opinion on causation. From Sommer‘s testimony as a whole, even without referencing the flow-bench testing, the jury could draw the inference that the loss of aircraft power was the result of the (undisputed) manufacturing defects present in the Lycoming pump and a substantial factor in the airplane crash and Kedrowski‘s resulting injuries. Moreover, the flaws that the district court found in the
Because we reverse the district court‘s decision to exclude Sommer‘s causation opinion, the evidence is no longer ” ‘so overwhelming on one side that rеasonable minds cannot differ as to the proper outcome.’ ” Lamb, 333 N.W.2d at 855 (citation omitted). We therefore also reverse the judgment as a matter of law in favor of Lycoming.
II.
Having concluded that the district court was within its discretion in finding that Sommer‘s flow-bench testing was foundationally unreliable, we turn to whether the erroneous admission of that testing is grounds to grant Lycoming a new trial.
We may order a new trial when reversing judgment as a matter of law.
“Entitlement to a new trial on the grounds of improper evidentiary rulings rests upon the complaining party‘s ability to demonstrate prejudicial error.” City of Moorhead v. Red River Valley Co-op. Power Ass‘n, 830 N.W.2d 32, 39–40 (Minn. 2013) (citation omitted) (internal quotation marks omitted); seе also
Here, Lycoming correctly asserts that Sommer‘s flow-bench testing “was the only test that could quantify a shortfall in fuel flow.” Moreover, Kedrowski relies heavily on the flow-bench testing, asserting that it showed that the “accident fuel pump was incapable of providing sufficient fuel to meet the engine‘s demands for takeoff and climb.” The only test that quantified the amount of fuel that the defective pump was capable of supplying to the engine—an issue central to this case—was not either “merely repetitious,” Poppenhagen, 220 N.W.2d at 285, or “irrelevant,” Savings Bank of Kewanee, Ill. v. Schaal, 195 N.W. 141, 142 (Minn. 1923). The admission of Sommer‘s flow-bench testing “might reasonably have influenced the jury and changed the result of the trial,” Estate of Baker, 724 N.W.2d at 9, spеcifically on the issue of causation. Therefore, the admission of the flow-bench testing was prejudicial.
A new trial may be granted “on all or part of the issues.”
But there can be only one grant of a new trial on the issue of liability. Because we conclude that a new trial is necessary, Kedrowski‘s challenge to the district court‘s order that granted a new trial on liability based on prejudicial misconduct by Kedrowski‘s trial counsel, an issue that the court of appeals did not address, is moot. Therefore, on remand, the court of appeals need only address whether a new trial is warranted on the issue of damages. Cf. Baker v. Baker, 753 N.W.2d 644, 653 (Minn. 2008) (remanding to court of appeals to address unresolved arguments that were not before our court).
CONCLUSION
For the foregoing reasons, we reverse the judgment granted as a matter of law in favor of Lycoming, order a new trial on the issue of liability, and remand to the court of appeals to address whether a new trial also is warranted on the issue of damages.
Reversed and remanded.