Hypothesize a car crash case. The only witness says that the light was red. The party with the burden of proving that the light was green cannot possibly prevail, so there’s no reason to have a trial. That case can be decided on summary judgment, right?

Not according to the plaintiffs we encounter in drug and device product liability cases.

Hypothesize a prescription drug case. The treating physician says that he or she was aware of the risk of the side effect that the plaintiff claims to have suffered. No additional warnings would have changed the treater’s decision to prescribe the drug or otherwise act as he did. Plaintiff bears the burden of proving “but for” causation – that a changed warning would have altered the treater’s conduct in a way that would have prevented injury to the plaintiff. Plaintiff cannot possibly prevail, so there’s no reason to have a trial. That case can be decided on summary judgment, right?

Not so fast, say our typical plaintiffs. Counsel says that the treating physician is somehow biased – he’s trying to avoid malpractice exposure; received a grant from the drug manufacturer to support his research; received free drug samples from the manufacturer; received an honorarium for speaking at a medical education seminar about one of the manufacturer’s drugs; whatever. Counsel says that he will cross-examine the heck out of the treater at trial, which will cause the jury to disbelieve the treater and render a plaintiff’s verdict. That possibility, says plaintiff’s counsel, should preclude granting summary judgment.

Nonsense. In the drug case, like the car crash case, there is no possibility that the plaintiff can carry the burden of presenting affirmative proof of his case. No matter how badly the treating physician is discredited on cross-examination, there is no possibility that the plaintiff can present proof that a changed warning would have altered the physician’s conduct. The drug manufacturer is entitled to summary judgment.

Happily, the cases typically so hold. For example, in Plummer v. Lederle Laboratories, 819 F.2d 249 (2d Cir.), cert. denied, 484 U.S. 898 (1987), the treating physician testified that “giving the[] warnings . . . wasn’t necessary” because the risks were small and a stronger warning could “scare off patients from bringing children in for future vaccinations, which . . . were much more important than the warning.” Id. at 352 (citation omitted). To establish causation, that plaintiff asserted that the treating physician’s “testimony that he had a practice of failing to warn his patients of the risk of contact polio should not be credited because he was an interested witness.” Id. at 359. The Second Circuit disagreed, stating that the treating physician’s “testimony was the only testimony on the issue of proximate cause. Even if the jury failed to credit him, [plaintiff] ha[d] not proven an essential element of his case. Furthermore, even if the warnings had been stronger, a reasonable jury could not have concluded that [the treating physician] would have warned the vaccinee’s mother.” Id. The Second Circuit therefore vacated a plaintiff’s verdict and directed the entry of judgment for the defendant.

Similarly, Wyeth-Ayerst Labs. Co. v. Medrano, 28 S.W. 3d 87 (Tex. App. – Texarkana 2000, no pet.), reversed a plaintiff’s jury verdict. Medrano found that, after the treating physician “testified that the information would not have affected her decision,” the defendant “was entitled to a directed verdict” because the plaintiff had, “as a matter of law, . . . failed to prove that . . . warnings were the cause of her injuries.” Id. at 95; see also Alexander v. Smith & Nephew, P.L.C., 98 F. Supp. 2d 1310, 1320 n.12 (N.D. Okla. 2000) (“disregard[ing] [the treating physician’s] testimony . . . would not correct Plaintiff’s failure to put forth any issue of material fact warranting submission of her case to the jury.”); Windham v. Wyeth Labs., Inc., 786 F. Supp. 607, 612 (S.D. Miss. 1992) (rejecting claim that “jury should determine whether an additional warning would have changed [treating physician’s] course of conduct;” “this is not a question for the jury in view of [the physician’s] unequivocal testimony”).

“[M]erely recit[ing] the incantation, ‘Credibility,’ and hav[ing] a trial on the hope that a jury may disbelieve factually contested proof” is insufficient to defeat summary judgment. Curl v. IBM, 517 F.2d 212, 214 (5th Cir. 1975) (citations omitted), cert. denied, 425 U.S. 943 (1976).

So now we won’t have to spend time quibbling about that any more, right?