The U.S. Supreme Court has injected some sanity into the murky, bitter and exorbitantly expensive world of product liability litigation. In what may be the most significant product liability decision of the past decade, the court agreed with Kumho Tire U.S.A. Inc. and Hercules Tire & Rubber Co. that all expert testimony—not just scientific evidence—should be based on accepted, observable fact.
This is a welcome decision because it protects the rights not only of corporate defendants, but also of wronged and injured plaintiffs.
The ruling gives trial judges broad discretion to determine what constitutes sound, relevant expert testimony. This means there are no hard-and-fast rules by which all expert witnesses must stand or fall. If a tire engineer is called to testify, he doesn't have to have a Ph.D. in polymer science or have published articles on tire engineering in scholarly journals. His experience and knowledge in the field are all that matters.
On the other hand, the guidelines affirmed by the high court strongly discourage expert testimony based on theories that lack wide acceptance. If a witness believes that a blown tire must have had a defect because the moon was in Virgo that night, the judge has every right—indeed the duty—to disqualify that witness, no matter if he bills himself as scientist, technician or Hollywood's No. 1 astrologer.
Crackpots, ambulance chasers and greedy corporations won't like this decision. But responsible product manufacturers, expert witnesses with sound credentials, and honest attorneys and consumers with a legitimate grievance will benefit from the ruling.
The Kumho decision is a victory for common sense and sound science.