Expert TestimonyU.S. District Court Judge Amul R. Thapar in the Eastern District of Kentucky asked these questions when ruling in a recent case dealing with expert testimony:

  • How should one attach a toilet seat to a toilet bowl?
  • Is a plastic bolt sufficient to do the job? Or is a metal bolt the way to go?
  • How should the bolt be designed?

Judge Thapar acknowledged that if you found these questions difficult to answer, “You are not alone.” This proved the point of his ruling that an ordinary person doesn’t know the answers to these technical questions. Rather, specialized, expert knowledge is needed to correctly answer them. In this case, the plaintiff failed to provide an expert on the subject, and without an expert, the jury would be forced to guess and speculate as to the answers, the judge wrote. “Such guesswork is impermissible under Kentucky law,” Judge Thapar held and granted the defendant’s motion for summary judgment.

Plaintiff claimed that he sustained injuries when a defective toilet seat he purchased at Defendant’s store broke. Plaintiff alleges that Defendant designed and manufactured the defective toilet seat and that it failed to adequately warn him of the risk associated with using it. Defendant moved for summary judgment, arguing that there was no genuine issue of material fact in the case because Plaintiff failed to disclose an expert witness by the required deadline. Without an expert witness, Defendant argued, Plaintiff couldn’t prove that the toilet seat was defective or that the defect caused his injury.

Judge Thapar agreed and wrote in his opinion that under Kentucky law, which governed the case, there are three recognized theories of product liability: defective design, defective manufacture, and failure to warn. Each of the accepted theories of recovery requires the plaintiff to prove the presence of a defect in the product, and here if Plaintiff couldn’t prove an essential element of his case at trial—the presence of a defect—Defendant is entitled to summary judgment.

Expert witnesses are “generally necessary” in a Kentucky products liability case to prove the presence of a defect because evidence that induces mere “surmise or speculation” is not sufficient to establish that a defect exists. Instead, Kentucky law requires a party to produce an expert witness when a subject is of the type which “requires scientific or specialized knowledge and which cannot be determined intelligently from testimony on the basis of ordinary knowledge gained in the ordinary affairs of life…” A plaintiff must put forth expert testimony unless a defect is of the type that the jury can comprehend “as well as a specially trained expert could,” Judge Thapar wrote, quoting Burgett v. Troy-Bilt LLC (E.D. Ky. 2013).

In light of this, the judge explained that the question presented here was whether an ordinary person is familiar enough with the principles of toilet seat engineering to know whether a toilet seat is defective. Plaintiff alleged that the seat was defective because the toilet seat had “plastic bolts, instead of brass or another metal, to connect it to the toilet itself . . . .” But Judge Thapar went on to say:

Such matters are not within the realm of knowledge of the ordinary person. As Plaintiff’s own theory of the defect illustrates, understanding how and why the plastic bolt was defective requires extensive technical knowledge: a person must understand the components of the toilet seat, how these components were put together, and whether a plastic bolt was sufficiently strong to attach these components to one another. A person must also understand the engineering intricacies of bolts and screws, including how to design and/or manufacture them to maximize their structural integrity, and how deep the Phillips head of such a component should be. Courts applying Kentucky law have required expert testimony for far less technical matters than these.

Without expert testimony, Plaintiff would merely be asking the jury to speculate, suppose, or surmise that there was a defect in the toilet seat. This type of guesswork isn’t allowed under Kentucky law, Judge Thapar held. Thus, because Plaintiff failed to disclose an expert to testify about the toilet seat defect, and such an expert is necessary for Plaintiff to establish an essential element of his case, Defendant’s motion for summary judgment was granted.


Denver Wells v. Wal-M art Stores, 2016 U.S. Dist. LEXIS 49544 (E.D. Ky April 13, 2016)