Expert Article Library

Speculation as to Potential Accident Causation Ruled Inadmissible

Case Name: Boss v. Nissan North America (Click here for the full text of the case)

Court: United States Court of Appeals for the 4th Circuit

Date: May 22, 2007

Expert: Automobile Experts. Gerald Rosenbluth, Richard Tessmann, Dean Jacobson, and David Leonard

Issue: Whether the testimony of the experts listed above on the potential cause of a power-steering malfunction is admissible.

Summary of case: Plaintiff was severely injured in the rollover of a Nissan Sentra. Plaintiff alleged that Nissan was negligent in the design of the Sentra’s power-steering system and this negligence caused the rollover.

Role of the experts: The experts planned to testify that “a particle lodged in the power steering system’s spool valve caused a steering malfunction.” This testimony was essential to Boss’s case.

Challenges to the Expert's testimony: The lower court disqualified Boss’s four expert witnesses at the motion of Nissan. The reasoning behind the 4th Circuit’s affirmation of that decision was that the testimony was speculative and there is no physical evidence of a “particle jam” in the power-steering system of the car. The court reasoned further that there is no scientific/engineering community consensus to support the theory and an NHTSA study “determined that particle jamming did not pose a risk to drivers.” The 4th Circuit affirmed the disqualification of Boss’s expert witnesses.

Summary prepared by C. Wood, Student, University of California, Hastings College of the Law