Product liability expert witness was erroneously excluded: Seventh Circuit
[As per the ruling in Daubert v. Merrell Dow Pharmaceuticals] the district court is responsible for acting as a gatekeeper to ensure that all admitted expert testimony satisfies Rule 702 reliability and relevance requirements. [But] trial judges acting as gatekeepers do not assume the role of St. Peter at the gates of heaven, performing a searching inquiry into the depth of an expert witness’s soul that would inexorably lead to evaluating witness credibility and weight of the evidence, the ageless role of the jury.
Saying so, the Seventh Circuit concluded that the district judge’s decision to exclude the Plaintiff’s product liability expert witness testimony in the case of Stollings v. Ryobi Technologies, Inc. was too great an intrusion into the role of the jury. His testimony was both reliable and relevant and should not have been excluded under Rule 702.
Background of the case
Upon losing his fingers in a table saw accident, Plaintiff Brandon Stollings sued the saw manufacturer, Defendant Ryobi Technologies, alleging that it had failed to equip the saw with either of two safety features: a riving knife (a small blade that holds the cut in the wood open to prevent kickbacks) and automatic braking technology (a safety system that automatically stops the saw blade upon contact with human tissue). A jury returned a verdict in favor of Defendant.
Plaintiff appealed, saying the district court made three reversible errors: (1) failing to stop Defendant from arguing to the jury that Plaintiff’s counsel had brought the case as part of a “Joint Venture” with the inventor of the automatic braking technology to force saw manufacturers to license the technology, and admitting hearsay evidence to support this improper argument; (2) excluding the testimony of one of Plaintiff’s expert witnesses; and (3) giving two erroneous jury instructions.
The product liability expert witness testimony and its methodology
Plaintiff’s product liability expert witness John Graham testified that including automatic braking technology on all power saws would be socially beneficial as the average cost of accidents per saw that would be prevented by the technology exceeded the cost of the braking system. He estimated that saws that lack automatic braking technology cost society an average of $753 in accident costs over the lifetime of the average saw. Therefore his conclusion was that it would make economic sense to install the technology on all saws if the cost of doing so was less than $753 per saw.
Graham also described how he reached his conclusion by calculating the average cost of a table saw injury (medical costs, lost wages, pain and suffering, and litigation costs). Next he multiplied this figure by the likelihood that a saw user would suffer an injury over the lifetime of a saw, yielding an estimate of the societal costs of injury per table saw. He then discounted this number by the effectiveness rate of the automatic braking technology, which he estimated to be 90 percent. The result was an estimate of the average societal costs of injuries per saw that occur because the technology is not installed.
The Illinois district judge found Graham’s testimony inadmissible under Rule 702 as not reliable or relevant for the trier of fact.
Review by the Court of Appeals
Going into the details of the role and power of a district court, the Seventh Circuit held
Rule 702’s requirement that the district judge determine that the expert used reliable methods does not ordinarily extend to the reliability of the conclusions those methods produce—that is, whether the conclusions are unimpeachable. An expert may provide expert testimony based on a valid and properly applied methodology and still offer a conclusion that is subject to doubt. It is the role of the jury to weigh these sources of doubt. … The judge should permit the jury to weigh the strength of the expert’s conclusions, provided such shortcomings are within the realm of a lay juror’s understanding. In this case, the judge’s exclusion of Graham’s expert testimony on reliability grounds intruded too far into the province of the jury. Although the 90 percent figure was undoubtedly a rough estimate, it is also clear that Graham’s bottom-line estimate of societal costs of saw accidents was so high that his opinion would have remained essentially the same even if the effectiveness rate were actually quite a bit lower.
As for the factor of reliability, the Court noted that relevance of an issue in a case was a question of substantive state law whereas relevance of evidence offered in resolving the issue was a procedural question governed by the Federal Rules of Evidence. Under the latter, testimony is relevant as long as it “has any tendency to make a fact more or less probable” than it would otherwise be (see Rule 401 and 702). Graham’s testimony, the Court decided, “satisfied this liberal relevance standard because it would have helped the jury weigh the saw’s utility by providing the jury with a basis to appreciate the saw’s costs to society, which is relevant under Illinois law.”
It was decided that the exclusion of Plaintiff’s product liability expert witness was an abuse of discretion on the district court’s part. Accordingly, the judgment was vacated and the case was remanded back for a fresh trial.
** Written for the web by the EWG Editorial Team
***Special thanks to James C. Feldman, CPA/ABV, CFF, MBA for submitting this case for coverage.