By Dale Campbell

Intellectual property litigation relies heavily upon the use of expert testimony. The Ninth Circuit Court of Appeals recently analyzed the intersection of Federal Rules of Evidence, Rule 702 and the ruling in Daubert v. Merrill Dow Pharmaceuticals, Inc., 509 U.S. 579 (1993) (“Daubert”) concerning the admissibility of expert testimony and Federal Rules of Civil Procedure, Rule 56 for summary judgment. Stillwell v. Smith & Nephew, Inc., 482 F.3d 1187 (9th Cir. 2007). Admissibility of expert testimony must be carefully evaluated for reliability and helpfulness, but that is different than the analysis for whether a triable issue of fact is established.



In Stillwell, the plaintiff had both legs broken in a car accident. The fractures were stabilized with two reconstruction nails. The nails failed during the healing process, and plaintiff brought suit against the nail manufacturer alleging claims for strict liability, negligence, and breach of warranty.

Defendants sought summary judgment on the grounds that plaintiff could not establish causation. Plaintiff offered the testimony of a metallurgical expert who testified that the nails suffered from correctible design and manufacturing defects that shortened their life. The expert could not quantify the length by which the life of the nails was shortened.  Plaintiff’s expert repeatedly testified that his expertise was in metallurgy as opposed to medicine or biomechanical engineering.

Defendants sought to exclude the testimony of plaintiff’s expert under Federal Rules of Evidence, Rule 702 and under the holdings in Daubert. Plaintiff’s expert had repeatedly acknowledged that his expertise was in metallurgy and not biomechanical engineering. The expert’s own testimony established that he did not have the expertise to testify regarding the design of the nail as a medical device; he could only analyze it with respect to its metallurgical qualities. The expert admitted he was not qualified to challenge the testimony of the medical doctors that the nails did not fail during the time in which plaintiff’s fractures should have healed and that other unforeseen and unexpected circumstances delayed plaintiff’s healing process. Defendants argued that plaintiff’s expert was not qualified to testify regarding the design, manufacture, or use of the nail as a medical device. 

The district court, applying Daubert, concluded that the expert “acknowledged that he lacked the expertise to determine whether the nails served the biomechanical purpose for which they were designed.” The district court found that the question was not whether the nail would suffer fatigue failure, but rather whether the nail was designed to fail only after it succeeded in supporting the union of the fractured bone. The court excluded the expert’s testimony and granted summary judgment for defendants. 

Plaintiff appealed on the sole ground that the court improperly excluded her expert’s testimony. An exclusion of testimony is an application of a rule of evidence that the Ninth Circuit reviews for abuse of discretion. (United States v. Prime, 431 F.3d 1147, 1152 (9th Cir. 2005).)

The Ninth Circuit agreed that the district court improperly excluded the expert’s testimony. Federal Rules of Evidence, Rule 702 permits testimony by experts qualified by “knowledge, skill, expertise, training, or education” to testify on matters that will “assist the trier of fact to understand the evidence or to determine a fact in issue.” Rule 702 embodies “the twin concerns of ‘reliability’ and ‘helpfulness.’” (United States v. Mitchell, 355 F.3d 215, 234 (3d Cir. 2004).) The question of reliability, however, is “not the correctness of the expert’s conclusion, but the soundness of his methodology.” (Daubert v. Merrill Dow Pharmacy, 43 F.3d 1311, 1318 (9th Cir. 1995).) The Ninth Circuit found that the district court focused on the helpfulness, rather than the reliability, of the expert’s testimony in excluding the testimony. The district court improperly blended the rules of admissibility under Federal Rules of Evidence, Rule 702, with the standard for summary judgment under Federal Rules of Civil Procedure, Rule 56. The Ninth Circuit found that a “[d]istrict court may not exclude expert testimony simply because the court can, at the time of summary judgment, determine that the testimony does not result in a triable issue of fact.” The appellate court noted that, in focusing on the eventual merit of plaintiff’s claims, the district court improperly required the expert testimony to establish not only alleged defects, but also causation.

Although plaintiff won the Rule 702 battle, she lost the war. The Ninth Circuit went on to say that this was a “rare case in which it is proper for [the appellate court] to exercise our discretion to consider a legal issue for the first time on appeal.” The court evaluated the evidence submitted with respect to causation and found that the underlying issue common to all of plaintiff’s claims was the existence of a defect in relation to the product’s intended purpose. The plaintiff’s evidence that the nail contained a design defect that shortened its life was not adequate to refute defendants’ evidence that the nail performed as intended and that the nail’s failure before the bone’s healing is a rare event.

The analysis in Stillwell highlights the different analysis concerning the admissibility of expert testimony as compared to the ultimate legal question. This distinction is an important one for trial attorneys in preparing to use any expert testimony, be it in summary judgment, trial, or motions for interim relief. The final decision in Stillwell left plaintiff with a hollow victory under the Rule 702, but losing on causation.  Proper understanding of the difference between the “reliability” and the “helpfulness” dual prongs is critical to maximize the value of expert testimony.