Utah Bar Journal

In two recent cases we litigated - one in the Federal District Court, District of Utah and one in the Third Judicial District Court for Summit County - the plaintiffs tried to bar defense expert "causation" opinions because the defense experts did not testify in terms of "probabilities." In moving in limine, the plaintiffs cited several Utah state court opinions excluding expert testimony where the expert only testified as to "possible" causes of injury. However, in both recent cases, Federal District Court Judge David Sam and Utah State Judge Robert Hilder declined respectively to apply those prior Utah opinions and denied plaintiffs' motions in limine. These judges noted that every case cited by plaintiffs, while barring the expert's testimony, involved a plaintiff's expert, not a defense expert. This distinction controlled, according to Judges Sam and Hilder, because the defendant, of course, does not have the "burden of proof." Therefore, defense experts do not have to testify in terms of "probabilities"; only plaintiffs' experts do. See Nelson v. Salt Lake City, et al., 919 P.2d 568, 574 (Utah 1996) ("plaintiff in general has the burden of proof [not defendant] . . . and must introduce evidence which affords a reasonable basis for the conclusion that [whatever plaintiff is alleging] is more likely than not [true]").

Although Utah courts are clear that plaintiffs' experts must testify in terms of "probabilities" rather than "possibilities," there is no published Utah opinion specifically addressing defense experts' testimonial obligations. However, other courts in the United States, both federal and state, hold consistently that requiring defense experts to testify only in terms of "probabilities" would result in an impermissible shifting of the burden of proof from plaintiff to defendant. Although each case cited below involves medical malpractice claims, courts here in Utah are now willing to apply the reasoning of these cases generally to other negligence-based claims.

In Wilder v. Warren Eberhart, M.D., 977 F.2d 673, 676-677 (1st Cir. 1992), the First Circuit Court of Appeals, quoting from Tzimas v. Coiffures By Michael, 606 A.2d 1082, 1084 (N.H. 1992), agreed that:

[T]he plaintiff in a negligence action bears the burden of producing evidence "to prove that it is more likely than not that [plaintiff's] injury was' caused by the defendant's negligence. Defendant need not prove another cause, he only has to convince the trier of fact that the alleged negligence was not the legal cause of the injury. In proving such a case, a defendant may produce other "possible" causes of the plaintiff's injury. These other possible causes need not be proved with certainty or more probably than not. To fashion such a rule would unduly tie a defendant's hands in rebutting a plaintiff's case, where as here, plaintiff's expert testifies that no other cause could have caused plaintiff's injury. The burden would then shift and defendant would then bear the burden of positively proving that another specific cause, not the negligence established by plaintiff's expert, caused the injury.

Certainly, this is much more than what should be required of a defendant in rebutting a plaintiff's evidence.

See also Salker v. Anesthesiology Associates, et al., 50 S.W.3d 210, 214 (Ky. Ct. App. 2001) ("[D]efendant need not disprove causation. Rather, he must produce credible evidence which tends to discredit or rebut the plaintiff's evidence").

Similarly, in the Estate of Lawrence Hunter v. Jay Michael Ura, et al., 2003 Tenn. App. LEXIS 755, *75, the Tennessee Court of Appeals vacated a plaintiff's jury award, citing the trial court's erroneous decision to bar defense expert testimony concerning "alternative [possible] causes of [decedent's] death". The Hunter Court explained its decision by quoting the First Circuit's hypothetical example given in Wilder, see infra:

Were we to accept plaintiff's argument that once a plaintiff puts on a prima facie case, a defendant cannot rebut it without proving another cause, the resulting inequities would abound. For example, if ninety-nine out of one hundred medical experts agreed that there were four equally possible causes of a certain injury, A, B, C and D, and plaintiff produces the one expert who conclusively states that A was the certain cause of injury, defendant would be precluded from presenting the testimony of any of the other ninety-nine experts, unless they would testify that B, C, or D was the cause of the injury. Even if all of defendant's experts were prepared to testify that any of the possible causes A, B, C, or D, could have equally caused plaintiff's injury, so long as none would be prepared to state that one particular cause, other than that professed by plaintiff more probably than not caused plaintiff's injury, then defendant's experts would not be able to testify at all as to causation.

Id. at *65. See also Haas v. Zaccaria, 659 So.2d 1130, 1133 (Fla. 1995) ("even assuming that 'reasonable medical probability' is part of a claimant's burden of proving a claim of medical negligence, we do not agree that such a burden logically compels the conclusion that the defendant doctor is precluded from offering evidence of possible explanations other than his own individual or joint negligence"). (Italics in original).

In both of our cases, Judge Sam's and Judge Hilder's respective rulings relying on the reasoning of these out-of-state opinions were critical because they allowed us as defense counsel to present alternative, "possible" causation theories for the plaintiffs' injuries sustained while skiing. In one case, we asserted at trial, through our expert orthopedic witness, that based on Plaintiff's own MRI films, plaintiff might have sustained her injury prior to the subject incident. In the other case (also a ski resort defense case), our expert ski patrol witness was permitted by Judge Sam to testify concerning the "possible" reason for decedent's (a skier) unconscious condition prior to sliding into a stationary object allegedly causing his death. Thus, while defense experts certainly can testify in terms of "probabilities," they are not required to do so, and may instead offer other, alternative "possibilities" to establish doubt in the jurors' minds about plaintiffs' claims.