Background
Paul Johnson was severely injured while operating Ridge Tool Manufacturing Company’s K-6200 drain-cleaning machine. Johnson had not read the user manual and used his employer’s oversized gloves instead of the gloves supplied by Ridge Tool, although he had read the warning label on the machine. While he supported the rotating cable with his hand, his glove became entangled, twisting his arm and body.
Johnson sued under strict-liability, negligence, and failure-to-warn theories. Mechanical engineer Chad Jones proposed a fixed coil-spring guard as a safer alternative design, while human-factors professional Cynthia Rando criticized aspects of the manual and the supplied gloves. The district court excluded both experts under Federal Rule of Evidence 702 and granted Ridge Tool summary judgment.
The Court’s Holding
The Seventh Circuit affirmed the exclusion of both experts. Jones neither tested nor modeled his proposed guard and did not adequately analyze its compatibility, costs, maintenance, risks, relative safety, or prevalence within the industry. Merely identifying three competitor machines with fixed guards did not reliably establish feasibility or an industry standard, particularly because Jones supplied no denominator showing how many competing machines lacked that feature.
Rando’s opinions about the manual could not establish causation because Johnson never read it, and her report did not meaningfully evaluate the warning label he did read. She also failed to draft or test an alternative warning. Without the excluded testimony, Johnson did not independently develop his negligence and design-defect theories on appeal, and his failure-to-warn theory rested only on the existing label and his assertion that it was inadequate. That evidence did not permit a reasonable inference that a different warning would have prevented his injury, so summary judgment was proper.
Key Takeaways
- Under the 2023 amendments to Rule 702, proponents must show by a preponderance of the evidence that expert testimony satisfies the rule’s admissibility requirements and remains within the bounds of a reliable methodology.
- An expert may rely on comparable designs already in the marketplace instead of conducting independent testing, but the expert still needs a reliable analytical basis beyond identifying a few competing products.
- A failure-to-warn plaintiff must present evidence supporting a reasonable inference that an adequate warning would have prevented the injury; conclusory criticism of the existing warning is insufficient.
Why It Matters
The decision emphasizes the Seventh Circuit’s rigorous application of amended Rule 702 in product-liability cases. Marketplace examples may support an alternative-design opinion, but they do not excuse an expert from analyzing feasibility, comparative safety, compatibility, costs, and industry prevalence.
The opinion also highlights the connection between expert exclusion and summary judgment. When expert testimony supplies the essential support for defect or warning theories, methodological shortcomings can leave the plaintiff unable to prove defect, inadequacy, or causation.