Expert witnesses are frequently called upon to testify in personal injury cases when the knowledge that they possess (from their area of specialty) can help substantiate a certain aspect (or aspects) of an injury claim. These types of witnesses derive their credibility from their education, experience, skills, knowledge, training, and often certifications in a particular field.
The testimony of a witness that qualifies as an “expert” is usually given considerable weight by the court because they are thought of as authorities on matters pertaining to their occupation or field of study. Because of this, their opinions are often sought after by litigants who want to further prove various aspects of their case.
While expert witness testimony can provide a major boost for a claimant’s case, there are times when their testimony may not help at all. For example, an expert witness cannot simply make wild assertions that have no basis in fact and ask the court to trust them based solely on their qualifications. There must be some standard that expert witnesses must meet in order for the court to take their claims seriously.
Case Study: 11th Circuit Court of Appeals Affirms Exclusion of Expert Witness Testimony in Product Liability Claim
Recently, the 11th Circuit Court of Appeals affirmed a lower court ruling that excluded the testimony of an expert witness in the case of Sheila A. Knepfle v. J & P Cycles, LLC, et al, No. 21-11996 (2022). This was a product liability action in which the plaintiff sought to have the expert testify that the “D-Ring” closure on a motorcycle helmet chinstrap was defective.
During his testimony, the expert failed to identify a single generally accepted test, peer-reviewed article, or independent study that supported his opinion on the design defect or theory of events. The court noted that the expert failed to measure critical helmet components or perform tests to confirm his theories regarding the mechanism of injury.
Ultimately, the court found the expert was academically qualified to testify; however, the court excluded the expert’s testimony because of the novel and untested theories used to reach his conclusion.
In 1993, the US Supreme Court addressed the issue of the admissibility of expert testimony in the case of Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579 (1993). The court held that expert testimony must be reliable and that a valid scientific link must be established between their testimony and the facts of a given case.
Since trial judges are compelled to act as “gatekeepers” with regard to the reliability and relevance of expert testimony, the court laid out a number of factors that judges should consider:
- Whether the theory or technique in question can be and has been tested.
- Whether the theory or technique has been subjected to peer review and publication.
- The theory or technique’s known or potential error rate.
- The existence and maintenance of standards controlling its operation.
- Whether the theory or technique is widely accepted in the relevant scientific community.
The 11th Circuit ruling in the recent product liability action seems to be in keeping with the standards that were set a couple of decades ago by the Supreme Court, and the ruling serves as a cautionary warning to expert witnesses and those who call on them to testify in a personal injury claim.
Experts need to provide scientific background for their theories beyond their own education or testing. In addition, the opinions and methodologies that they present should be supported by peer-reviewed literature or learned treatise sources common to their industry or field of study. Without these elements, there is a good chance that the expert witness testimony will be excluded by the court.