Case Explained: PAUL JOHNSON v. RIDGE TOOL MANUFACTURING COMPANY, INC

Court: United States Court of Appeals for the Seventh Circuit Filed: 2026-08-07 The Seventh Circuit affirmed the district court’s grant of summary judgment in favor of Ridge Tool Manufacturing Company, Inc., holding that the exclusion of the plaintiff’s expert witnesses under Federal Rule of Evidence 702 was proper and left the plaintiff with insufficient evidence to sustain his product liability, negligence, and failure-to-warn claims. The court applied the gatekeeping standard of Rule 702, as amended in 2023, which requires that expert testimony be based on sufficient facts, reliable principles and methods, and a reliable application of those methods to the case facts. Regarding the plaintiff’s design defect claim, the court found the mechanical engineer’s report inadmissible because it relied solely on the existence of similar designs in competitor products without testing feasibility, analyzing maintenance costs, or evaluating compatibility with the specific machine. The court distinguished this from precedent where testing was unnecessary because the alternative design was already in widespread use, noting that the plaintiff failed to provide a denominator for his industry comparison and offered no data on the safety relative to the actual machine. Regarding the failure-to-warn claim, the court found the human factors expert’s report unreliable because she opined on the inadequacy of the user manual without addressing the fact that the plaintiff never read it, and she failed to propose or test a specific alternative warning label that would have prevented the injury. The practical consequence is that the plaintiff’s appeal is dismissed and the district court’s summary judgment ruling stands. Without admissible expert testimony to support his theories of design defect or inadequate warnings, and lacking any alternative evidence such as a proposed better warning label, the plaintiff cannot meet the burden required to survive summary judgment under Illinois law. Do It For The Case Law is a news reporting service. Nothing in this episode constitutes legal advice.