Kline v. Zimmer (May 26, 2022, B302544)
Plaintiff claimed a hip implant manufactured by the defendant was defective and caused his continued pain. In response, defendant offered an expert who would testify to “possible” alternative causes of plaintiff’s pain. The defendant also sought to elicit testimony from plaintiff’s treating physicians as to alternative causes of plaintiff’s pain. The trial court, however, excluded “all medical opinions that were expressed to less than a reasonable medical probability.” As a result, the defendant was prevented from offering any expert testimony to rebut plaintiff’s evidence of causation and the plaintiff obtained a sizeable verdict.
The Court of Appeal reversed for a new trial. While the plaintiff in a personal injury case has the burden of establishing medical causation to a degree of reasonable medical probability, “[t]he same does not apply to a defendant’s efforts to challenge or undermine the plaintiff’s prima facie case.” A defendant has no obligation to put on any evidence, and only needs to demonstrate that the plaintiff’s evidence is insufficient to prove his injuries were more likely than not caused by the defendant. The defendant thus “should have been permitted to do so by offering expert opinions offered to less than a reasonable medical probability that [plaintiff’s] injuries may have been attributable to other causes.” “Such defense expert opinions could cast doubt on the accuracy and reliability of a plaintiff’s expert.”
The Court of Appeal additionally found that the error depriving the defendant of any causation defense was prejudicial as a matter of law: “The trial court’s categorical exclusion of Zimmer’s expert testimony on a central issue, which was beyond the experience of laypeople, deprived Zimmer of a fair trial and therefore constitutes structural error.”
