{1} Plаintiff Marta Lewis, acting as personal representative for decedent Martin C. Lewis, filed an action for wrongful death arising out of medical malpractice against Defendants Norberto R. Samson, Jr., M.D., and Raymond F. Ortiz, M.D. Following a jury verdict and judgment in favor of Defendants, Plaintiff appealed to the Court of Appeals. The Court of Appeals reversed the judgment and remanded for a new trial based on the conclusion that the district court abused its discretion in relation to a discovery ruling. Lewis v. Samson,
I. Facts and Proceedings
{2} In February 1994, Moses Griego stabbed Martin Lewis in the back eight times during a fight in Tucumcari, New Mexico. Seven of the eight stab wounds penetrated Lewis’s lungs. Following the stabbing, Lewis was treated by Defendants at the emergency room of Dan C. Trigg Memorial Hospital (Trigg Hospital) in Tucumcari. At some point during the treatment, Defendants telephoned the University of New Mexico Hospital (University Hоspital) to request an emergency transfer of Lewis for a thoracotomy. University Hospital informed Defendants that Lewis would not survive a ground transfer and sent a specialist to Trigg Hospital by plane. Defendants attempted to stabilize Lewis but did not perform a thoracotomy; instead, they awaited the arrival of the specialist. Approximately two hours later, the specialist arrived and immediately performed a thoracotomy, but Lewis did not survive. Griego was later convicted of second degree murder for the stabbing.
{3} Plaintiff brought suit against Defendants, alleging medical negligence in their treatment of Lewis. Plaintiff also originally named University Hospital as a defendant and initially filed her complaint in October 1995 in the Second Judicial District. Following an amicable resolution of the claim against University Hospital, Plaintiff dismissed University Hospital as a defendant. Plaintiff then re-filed in the Tenth Judicial District in January 1997. The district court, in February 1997, set the trial date for July 14,1997; however, the court rescheduled the trial for January 1998 due to an inability to seat an impartial jury.
{4} At trial, Plaintiff attempted to establish Defendants’ negligence by introducing expert testimony that Defendants performed below the standard of care for a reasonable physician. Specifically, Plaintiffs expert testified that Defendants should have inserted chest tubes earlier, should have attempted to transfer Lewis more quickly, and should have attempted to perform a thoracotomy as a last resort. Plaintiffs expert testified that Lewis had a ninety percent chance of survival if he had received appropriate care. In response, Defendants testified that they were not properly trained to perform a thoracotomy, that they sought to transfer Lewis in a timely manner, and that they did not unduly delay the insertion of chest tubes. Defendant Samson, a general surgeon, testified that he had not performed a thoracotomy in sixteen years, that no physician had privileges to perform an open thoracotomy at Trigg Hospital at the time of the incident, and that the emergency room was not properly equipped and the staff not properly trained to perform an open thoracotomy. In addition, Defendants introduced expert testimony to support their contention that they performed within an acceptable range of medical care. Defendаnts’ expert testified that the timing of the insertion of chest tubes made no difference in the outcome of Lewis’s treatment. Defendants’ expert testified that nothing could have been done to save Lewis’s life given the number and severity of the stab wounds, the occurrence of the stabbing in the rural area of Tucumcari, and the unavailability of an experienced chest surgeon. With regard to the timeliness of seeking to transfer
II. Discovery Rulings
{5} This appeal implicates two separate discovery rulings made by the district court: (1) the partial granting of a defense motion to exclude witnesses due to a lack of timely disclosure; and (2) the denial of Plaintiffs motion to reopen discovery and to modify the discovery deadlines in a pretrial order. The Court of Appeals concluded that the district court abused its discretion in denying Plaintiffs motion to reopen discovery. Lewis,
A. Late Disclosure of Witnesses
{6} On February 12, 1996, Plaintiff responded to a list of interrogatories submitted by Defendant Samson which included a request to identify each witness whom Plaintiff intended to call at trial and a brief synopsis of their testimony. Plaintiff stated that she intended to call “any and all personnel from Dan Trigg Hospital. No other witnesses have been developed.” Plaintiff did not supplement her answer to this interrogatory during the course of litigation.
{7} Over one year later, on Mаrch 14, 1997, Defendant Ortiz requested that Plaintiff supplement her responses to interrogatories. Defendant Ortiz expressly identified in this letter that he was “primarily interested in [Plaintiffs] trial witnesses and exhibits.” Plaintiff failed to respond to this request. On May 30, 1997, approximately six weeks before the original trial date of July 14,1997, Plaintiff served Defendants a document entitled “Plaintiffs Witness List for Trial.” This list included fifteen witnesses that had not been previously disclosed by Plaintiff and were not personnel of Trigg Hospital. Even though the original trial date was imminent, Plaintiff failed to disclose the substance of these witnesses’ testimony but stated in a cover letter that “[t]hese are friends and colleagues only and will testify about Martin’s life.” Plaintiff further indicated that she would, “of course, not call all of them and [would] provide a final list, when determined, by the last part of June,” approximately two weeks before trial. Finally, Plaintiff informed Defendants that she would also be calling her expert witnesses. She attached a report from an economist, Dr. Brian McDonald, outlining his opinions concerning economic damages. Plaintiff had not previously disclosed this witness to Defendants, even though Dr. McDonald’s report was dated February 26,1997.
{8} On June 9,1997, Defendant Ortiz filed a motion to exclude the fifteen fact witnesses disclosed by Plaintiff on May 30, 1997. Defendant Ortiz argued that Plaintiffs late disclosure of witnesses violated the rules of discovery and, due to the lack of specificity with respect to which of the witnesses would testify and the subject matter of the testimony, prejudiced Defendants’ ability to depose Plaintiff’s witnesses and to prepare rebuttal. In response to this motion, on June 11,1997, Plaintiff agreed not to call the fifteen fact witnesses identified on May 30,1997, but still intended to call the late-identified expert, Dr. McDonald, as well as Penny Griner, an employee of University Hospital, and Sharon Faison, an employee of Trigg Hospital. Defendant Samson then filed a motion to ex-elude these three witnesses on the basis of late disclosure.
{9} The district court held a hearing on the motion to exclude
{10} In response to Plaintiffs arguments, Defendant Samson contended that an oversight did not excuse Plaintiffs failure to disclose Dr. McDonald and Griner. Additionally, Defendants argued that Plaintiff was previously aware of the disputed issue of Defendant Ortiz’s telephone call to University Hospital and that Plaintiffs failure to identify Griner at an earlier date caused them to believe that all issues involving personnel from University Hospital had been resolved by Plaintiffs settlement of her claim against the hospital. Defendants also stated that Griner’s availability prior to the original trial date appeared questionable. Defendants thus contended that they would be prejudiced by Plaintiffs late disclosure of Griner. Defendants finally contended that Faison’s testimony would be cumulative of an admission made by Defendant Samson that rib spreaders were available at Trigg Hospital at the time of treatment.
{11} The district court ruled that, to the extent that Faison’s testimony would be cumulative of Defendant Samson’s admission, it would be excluded. The court also found that Plaintiff was aware of the issue of the telephone conversations with University Hospital from the very beginning of the case and that, as a result, Griner would be excluded due to Plaintiffs untimely disclosure. With respect to Dr. McDonald, the court indicated that Defendants had a right to view his report and that it was improper for Plaintiff to withhold the information. However, the court recognized that Dr. McDonald’s testimony would be important to Plaintiffs case and denied Defendants’ request to exclude Dr. McDonald’s testimony in the interest of fairness.
{12} Typically, under our Rules of Civil Procedure, “[a] party who has responded to a request for discovery with a response that was complete when made is under no duty to supplement the party’s response to include information thereafter acquired.” Rule 1-026(E) NMRA 2001. However, an exception to this general rule applies in this case.
A party is under a duty seasonably to supplement the party’s response with respect to any question directly addressed to the identity of each person expected to be called as a witness at trial, the subject matter on which the party is expected to testify and the substance of the party’s testimony.
Rule 1-026(E)(1). This exception applies to both fact witnesses and expert witnesses, the latter of which are subject to discovery as specifically provided in Rule l-026(B)(5)(a) (requiring that a party “identify each person whom the ... party еxpects to call as an expert witness at trial, to state the subject matter on which the expert is expected to testify, and to state the substance of the facts
{13} We review a trial court’s decision to impose discovery sanctions under Rule 1-037(B)(2) for an abuse of discretion. United Nuclear Corp. v. Gen. Atomic Co.,
{14} The record indicates that Plaintiff failed to supplement her answers to interrogatories concerning the identity of her witnesses at trial and therefore violated her duty under Rule 1-026(E)(1). Additionally, Plaintiff failed to respond to a specific request by Defendants to supplement her answers to interrogatories. With only approximately six weeks remaining before the original trial date, Plaintiff identified numerous previously undisclosed fact witnesses. At that same time, Plaintiff also offered a previously undisclosed expert witness, even though the date of the expert’s report clearly indicated Plaintiff’s prior awareness of this witness. Despite having the expert’s report, Plaintiff did not include this witness in her answers to interrogatories, did not supplement her answers to interrogatories to disclose this witness, and did not disclose the witness’s report, in violation of her duties under Rule l-026(B)(5)(a).
{15} Rule l-037(B)(2)(b) provides that a trial court may respond to an abuse of discovery by “refusing to allow the disobedient party to support or oppose designated claims or defenses, or prohibiting that party from introducing designated matters in evidence.” Additionally, we have said that, “[i]n any just search for truth, a trial court must have broad discretion to admit or refuse testimony of witnesses whose identity was not revealed in answers to pretrial interrogatories.” Montoya v. Super Save Warehouse Foods,
{16} The record indicates that the district court took into account the potential prejudice to Defendants from the discovery violations and the importance of the evidence to Plaintiffs case. The court also considered whether Plaintiffs conduct was excusable by ascertaining Plaintiffs prior awareness of the need for the late-disclosed witnesses. The court indicated an intention to ensure fairness to both parties. Based on these considerations, the district court entered the lesser sanction of excluding two of Plaintiffs witnesses, Griner and Faison, while allowing Plaintiff to call her third undisclosed witness, Dr. McDonald.
{17} In this case, Plaintiff demonstrated a repeated disregard for the rules of discovery. Cf Allred,
B. Pretrial Order and Reopening Discovery
{18} On June 18, 1997, the district court entered a pretrial order, which included the parties’ witness lists, and set a discovery deadline of June 27, 1997. Following the inability to seat a jury on the original trial date of July 14, 1997, and the postponement of trial until the following January, Plaintiff filed a motion to amend the pretrial order to allow additional discovery and the inclusion of more witnesses. In a brief in support of the motion, Plaintiff stated, “This court denied Plaintiff two witnesses because the witnesses were not named until six weeks prior to the scheduled beginning of the trial. Moreover, Plaintiff now wishes to add another witness from Amarillo to prove that Amarillo accepts patients from New Mexico____” Plaintiff contended “that counsel is oftentimes faced with the difficulty of addressing and dealing with supplemental information that comes to light after the deadline for discovery passes.” At a hearing on Plaintiffs motion, Plaintiff emphasized her request to call the witness from Amarillo but also indicated to the district court that she would like to call the specialist from University Hospital who flew to Tucumcari to treat Lewis, Dr. James Hanosh, apparently to testify about Defendant Ortiz’s telephone calls to University Hospital. Plaintiff had not spoken with Dr. Hanosh but apparently believed that he would provide information regarding University Hospital’s in-coming call procedure. Dr. Hanosh did not actually speak to Defendants on the telephone until 4:20 a.m. and had no personal knowledge about the subject of the 3:06 a.m. call. In addition to these witnesses, Plaintiff further hoped to reopen all of discovery through the day of trial. Plaintiff indicated that she was unaware of Defendant Ortiz’s claim that he called University Hospital at an earlier time and that she needed additional witnesses to respond to that claim. Plaintiff further contended that the district court’s earlier exclusion of Faison was based on the false premise
{19} The distinct court informed Plaintiff that “there’s a reason for the pretrial order ... [and] a reason for the time limits.” The court found that Plaintiff was previously aware of the information she sought to discover and that the pretrial order did not prevent Plaintiff from ascertaining the information prior to the entry of the pretrial order. However, the court afforded some relief to Plaintiff by ensuring that Plaintiffs existing witnesses would be able to testify about the possibility of a transfer to Amarillo, by instructing Defendant Samson to clarify his admission, and by informing Plaintiff that the court would give her some latitude in her impeachment of witnesses.
{20} The Court of Appeals determined that the district court did not abuse its discretion in relation to Faison and the witness from Amarillo because these witnesses would have provided cumulative testimony. Lems,
{21} In reviewing the district court’s ruling, we believe it is useful to separate Plaintiffs requests into two categories: (1) her request to add Griner and Faison as witnesses; and (2) her request to add the witness from Amarillo, to reopen discovery in general, and to add Dr. Hanosh as a witness. Addressing Plaintiffs first request, we note initially that Plaintiffs conduct in failing seasonably to disclose Griner and Faison as her witnesses, as well as Defendants’ motion to exclude these witnesses for abuse of discovery, occurred prior to the district court’s entry of the pretrial order. At the time of drafting the pretrial order, however, Defendants’ motion to exclude Griner and Faison was still pending before the district court. As a result, the pretrial order listed Griner and Faison as two of Plaintiffs witnesses. Subsequently, the district court ruled on Defendants’ motion and excluded Griner and Faison based on Plaintiffs abuse of discovery. Thus, the court’s original exclusion of Griner and Faison had no relationship to the pretrial order or the discovery deadline imposed pursuant to Rule 1-016 NMRA 2001. It was nоt the discovery deadline in the pretrial order that prevented Plaintiff from calling Griner and Faison as witnesses for the original trial date. Instead, Plaintiffs inability to call these witnesses stemmed from the district court’s decision to grant Defendants’ motion to exclude them as witnesses based on Plaintiffs abuse of discovery. As a result, we will review the motion to reopen discovery, as it relates to Griner and Faison, as a motion to reconsider the district court’s earlier decision to exclude these two witnesses due to Plaintiffs abuse of discovery.
{22} We do not believe the district court abused its discretion in denying the motion to reconsider. In ruling on the motion to reconsider, the court had before it the same issues presented at the hearing in June in relation to Plaintiffs multiple violations of the rules of discovery. With respect to Faison, the district court ascertained Defendant Samson’s intended meaning with respect to his admission about the rib spreaders. The court instructed Defendant Samson to clarify his admission to reflect his intended meaning and determined that the clarification would obviate the need for Faison’s testimony. We therefore agree with the Court of Appeals that the district сourt reasonably determined that Faison’s testimony would have been cumulative.
{23} With respect to Griner, Plaintiff provided no additional information about the substance of Griner’s testimony. Thus, from the district court’s perspective, based on Plaintiffs initial proffer at the hearing on the motion to exclude late-disclosed witnesses, it was unclear whether Griner’s testimony would have been favorable to Defendants or to Plaintiff. While it is certainly true that the degree of prejudice that would
{24} We highlight the fact that Plaintiff repeatedly breached her duties under the rules of discovery. See generally Allred,
{25} We now address the district court’s denial of Plaintiffs motion to reopen discovery regarding the other witnesses identified in Plaintiffs motion. Under Rule 1-016(E), a pretrial “order shall control the subsequent course of the action unless modified by a subsequent order. The order following a final pretrial conference shall be modified only to prevent manifest injustice.” “[B]y the time of entry of the pretrial order, our rules contemplate that the issues to be tried will have been identified.” Fahrbach v. Diamond Shamrock, Inc.,
1) whether trial is imminent, 2) whether the request is opposed, 3) whether the non-moving party would be prejudiced, 4) whether the moving party was diligent in obtaining discovery within the guidelines established by the court, 5) the foreseeabilityof the need for additional discovery in light of the time allowed for discovery by the district court, and 6) the likelihood that the discovery will lead to relevant evidencе.
Silr-Flo, Inc. v. SFHC, Inc.,
{26} With respect to reopening discovery generally until the day of trial, the district court clearly did not abuse its discretion in refusing Plaintiffs request. To have granted this request, the district court would have had to ignore the very purpose of entering a pretrial order. See Fahrbach,
{27} Turning to Plaintiffs request to add Dr. Hanosh to her list of witnesses, we review this issue in light of the six factors articulated above. While it is true, as the Court of Appeals observed, that trial was not imminent and there was not a great deal of potential prejudice to Defendants, see id. ¶ 29, Plaintiff admitted she was not diligent in obtaining discovery. Cf. Sil-Flo,
{28} However, the question we face is not whether we believe that a balancing of the relevant factors weighs in favor of one party or another. Our review is limited to deciding whether we are convinced that the trial court committed a clear error in judgment in its balancing of these factors. See Reaves,
{29} Under the applicable standard of review, we conclude that the district court reasonably determined that the factors weighed against Plaintiff and that Plaintiff failed to demonstrate a manifest injustice. Cf. Reaves,
III. Concurrent and Successive Tortfeasors
{30} Prior to trial, Plaintiff requested that the district court restrict Defendants from arguing that the tortious actions of Lewis’s assailant, Griego, caused Lewis’s injuries. Plaintiff agreed to stipulate that Lewis arrived at the hospital with stab wounds, but she objected to any evidence or argument concerning the source of the wounds. The court denied Plaintiffs motion. At the conclusion of the trial, the district court instructed the jury on the topic of comparative negligence in accordance with UJI 13-802D NMRA 2001. The Court оf Appeals made two separate rulings on this issue. First, the Court concluded that the district court’s denial of Plaintiffs pretrial request was erroneous. Lewis,
{31} The Court of Appeals concluded that both of its rulings on this issue were compelled by our opinion in Lujan v. Health-south Rehabilitation Corp.,
if the facts of a particular case warrant the argument by either a plaintiff or a defendant that the theory of liability is one of successive and not concurrent tortfeasor liability, or vice versa, then the party arguing such liability has the burden of adducing evidence not only of the negligence of the tortfeasor but of the divisibility or indivisibility of the injury.
Id. ¶ 56. Based on this construction of Lujan, the Court of Appeals determined with respect tо the present case that the district court should have ruled as a matter of law that Defendants were successive tortfeasors based on Plaintiffs mere allegation of an enhanced injury. Id. ¶¶41, 54,
{32} In New Mexico, the common law doctrines of contributory negligence and joint and several liability have been replaced with a system of pure comparative negligence and, with respect to concurrent tortfeasors, several liability. See NMSA 1978, § 41-3A-1(A) (1987); see also Scott v. Rizzo,
{34} With respect to claims against the subsequent tortfeasor, we adopted in Lujan the standard for enhanced injuries that the Court of Appeals had previously applied in Duran v. General Motors Corp.,
{35} Based on the principles articulated above, we conclude thаt the Court of Appeals erroneously concluded that Defendants could not introduce evidence of Griego’s fault. Defendants argued that Griego was wholly responsible for Lewis’s death. It is the plaintiffs burden in a negligence case to prove the element of proximate causation. See UJI 13-302B NMRA 2001. Thus, Defendants’ argument concerning Griego represents a basic proximate cause defense; if Griego was the sole cause of Lewis’s death, as Defendants argued, then Plaintiff would fail to establish that Defendants’ negligence proximately caused Lewis’s harm. In a typical negligence ease involving concurrent tortfeasors, the jury assesses whether each defendant’s negligence is a cause of the plaintiffs harm and, if so, then the jury compares the negligence of each tortfeasor in order to assign a percentage of fault. See UJI 13-2219 NMRA 2001. In an enhanced injury case, a jury does not compare the negligence of the tortfeasors for the enhanced injury, but the plaintiff must still prove that the physician’s negligence proximately caused an enhancement of the initial harm suffered at the hands of the original tortfeasor. Lujan,
{36} Plaintiff introduced evidence in this case, in the form of expert testimony, that Lewis would have survived but for Defendants’ negligent treatment. Defendants countered this theory through contrary expert testimony and by arguing to the jury that Griego alone was responsible for Lewis’s death. This is an issue of proximate cause, which is an issue on which Plaintiff bore the burden of proof and an issue that must be resolved by the jury. The Court of Appeals, although recognizing that Defendants’ argument related to proximate causation, Lewis,
{37} The Court of Appeals’ holding that any evidence of the initial tort must be excluded creates an impracticable, artificial inquiry which removes any context from the jury’s determination of causation. If, based on the two-part Lujan test, a plaintiff fails to prove that a physician’s negligence enhanced the original injury, then the original tortfeasor’s negligence is the sole proximate cause of the entire harm. Thus, because the issue of proximate cause rests with the jury and because the plaintiff bears the burden of demonstrating an enhancement of the original injury under Lujan, we conclude that a physician accused of subsequent medical negligence may rebut the plaintiffs evidence of causation through evidence of the initiаl tortfeasor’s responsibility for the entire harm.
{38} The Court of Appeals, based on its interpretation of Lujan, also concluded that
{39} In Duran, the injured party was involved in an initial car accident unrelated to the vehicle’s design. Duran,
[defendants are not liable for injuries caused by the initial impact and [damage to the vehicle] resulting therefrom. They are only liable, if at all, for that portion of the damage or injury caused by the defects over and above the damage or injury that probably would have occurred as a result of the [accident] without those defects. The [expert] does not address this in his testimony____
Id.
{40} Like Duran, Huddell also involved a crashworthiness claim against the manufacturer of a vehicle that was involved in an initial automоbile accident. Huddell,
Without proof to establish what injuries would have resulted from a non-defective [design], the plaintiff could not and did not establish what injuries resulted from the alleged defect____Without such proof, the jury could not have properly ... assessed responsibility against [the manufacturer] for the death of [the victim].
Id.
{41} As in Huddell, although Plaintiff introduced evidence that Lewis would have survived if he had received proper medical treatment, Plaintiff failed to demonstrate the extent of injuries that Lewis would have suffered in the absence of Defendant’s alleged medical negligence. The Court of Appeals explained in Duran that a failure of proof of this type will result in a directed verdict for a defendant. Duran,
{42} It appears that Plaintiffs basic strategy in this case was to attempt to hold Defendants’ jointly and severally liable for the entire harm initiated by Griego. Plaintiff sought to exclude all evidence of Griego’s fault and made no effort to prove the degree of enhancement of Lewis’s injuries caused by the alleged medical negligence. Plaintiff simply sought to hold Defendants liable for the entirety of Lewis’s damages for wrongful death. However, a theory of joint and several liability against a successive medical care provider for the entire harm suffered from both torts is antithetical to the policies underlying our opinion in Lujan and contrary to New Mexico’s adoption of several liability. “Although an original tortfeasor may be held liable for plaintiff’s entire harm, a medical care provider who negligently aggravates the plaintiff’s initial injuries is not jointly and severally liаble for the entire harm, but is liable only for the additional harm caused by the negligent treatment.” Lujan,
{43} The Court of Appeals recognized this aspect of Lujan. See Lewis,
{44} In this case, the district court did not err in denying Plaintiffs request to exclude evidence of Griego’s fault. Although it was error to instruct the jury on principles of comparative fault, this error had the effect of shifting Plaintiff’s burden of proving causation under Lujan to Defendants and therefore did not cause her prejudice.
IV. Conclusion
{45} The district court did not abuse its discretion in excluding witnesses in response to discovery violations by Plaintiff. The district court also did not abuse its discretion in denying Plaintiff’s motion to reopen discovery. Under Lujan, Plaintiff bore the burden of proving that Defendants, and not the initial stabbing by Griego, proximately caused Lewis’s death. As a result, Defendants were entitled to rely on evidence of Griego’s fault in their argument that Griego’s tortious actions were the sole proximate cause of Lewis’s death. Plaintiff bore the burden of demonstrating
{46} IT IS SO ORDERED.
Notes
. In contrast to our deference to trial courts, the Federal Rules of Civil Procedure provide for mandatory exclusion of undisclosed witnesses. See Fed.R.Civ.P. 37(c)(1) ("A party that without substantial justification fails to disclose information required by Rule 26(a) or 26(e)(1) shall not, unless such failure is harmless, be permitted to use as evidence at a trial, at a hearing, or on a motion any witness or information not so disclosed.”); Klonoskiv. Mahlab,
. In this case, the jury found by special verdict that Defendants were not negligеnt. Because the jury first considered whether Defendants were negligent and thus did not reach the separate question of whether Defendants' negligence proximately caused Lewis's death or the question of the relative percentage of fault attributable to Defendants as compared to Griego, the district court’s rulings regarding the admissibility of evidence of Griego’s fault and regarding the jury instructions on comparative fault, even if erroneous, would constitute harmless error. See Fahrhach,
. In particular, we need not examine in detail the distinction between concurrent and successive tortfeasors. Compare Lujan,
. The original tortfeasor is not liable for injuries caused by medical negligence that are so remote from the original injury as to be unforeseeable.
. There has been some disagreement as to whether this principle operates as a positive rule of law, and some courts have held that the principle is instead merely a product of the general rules of proximate causation. See Kemper Nat’l P & C Cos. v. Smith,