Challenging Expert Testimony

Practical Law Legal Update w-000-4712 (Approx. 3 pages)

Challenging Expert Testimony

by Practical Law Litigation

Published on 04 Aug 2015 • USA (National/Federal)

Expert testimony frequently is a crucial part of proving a claim or defense. Exclusion of expert testimony can result in dismissal of the entire case. A recent decision from the US District Court for the Southern District of Ohio illustrates several pitfalls to avoid when choosing an expert.

In Hutson v. Covidien Holding, Inc., No. 2:13-cv-895, (S.D. Ohio June 30, 2015), plaintiff brought a product liability action against Covidien, a needle manufacturer. Plaintiff Hutson had visited his dentist for a root canal and, as part of the procedure, the dentist administered anesthesia using a Covidien-made needle. Although the warnings accompanying the needle cautioned against bending the needle, Hutson's dentist still bent the needle prior to administering the anesthesia. The needle broke and a portion became lodged in Hutson's gum. The needle was ultimately removed by an oral surgeon.

Hutson sued Covidien, alleging that a manufacturing defect caused the needle to break. His sole expert was Alan Lipschultz, a professional engineer. Lipshultz offered the opinion that there were four potential causes for why the needle broke and three involved a manufacturing defect. However, there was insufficient data from the broken needle to rank the likelihood of the causes.

Lipschultz based his opinion on a report written by two metallurgists who:

Inspected the broken needle.
Tested exemplar needles under Lipschultz's observation.

Covidien moved to exclude Lipschultz's testimony and for summary judgment. Covidien argued that Lipschultz's testimony failed to meet the requirements of Federal Rule of Evidence (FRE) 702 and the Supreme Court's seminal decision in Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579 (1993) because the methodology used to test the exemplar needles was unreliable.

In granting the motion to exclude Lipschultz's testimony, the court agreed that the testimony was unreliable for several reasons:

The metallurgists' methodology was never tested, published or subject to peer review. It also was not supported by:
- a written protocol;
- a known or potential error rate; or
- evidence that it was generally accepted in the scientific community.
Lipschultz lacked relevant experience. He had no experience working with needles and never performed a failure analysis on stainless steel.
Lipschultz never identified how the needle was defective and could not eliminate the possibility of misuse by the dentist.
Lipschultz made no findings of his own and lacked any ability to assess the techniques used by the metallurgists. His testimony was nothing more than a regurgitation of the metallurgists' findings.

The court then granted Covidien's motion for summary judgment. Without expert testimony or any other evidence to establish a defect in the needle, Hutson was unable to prove a necessary element of his product liability claim.

This decision serves as a potent reminder that counsel must ensure that any expert testimony meets the requirements of FRE 702 and Daubert. Practical Law's Expert Toolkit includes various resources to help practitioners develop admissible expert testimony, including resources relating to:

Daubert motions.
Expert reports.
Expert depositions.

Challenging Expert Testimony | Practical Law