Net Opinion Nets Controversy (NJ)

The net opinion rule, well established in New Jersey Courts, requires the expert witness to give the “why and wherefore” of his expert opinion and not a mere conclusion. The expert’s opinion must not be solely based on the expert’s own personal view and experience, but must reference factual evidence.

In Jackson v. Jilco Trailer Leasing Co., plaintiff alleged that he was injured when a metal grip handle became detached while he was attempting to hoist himself up onto the rear of a tractor-trailer.  Plaintiff presented a metallurgical engineering expert to support his theories of product liability and negligence. The expert opined that the rivets used to attach the grip handle to the trailer failed because they were either not suitable for this particular use or they had been improperly installed. The trial court granted defendant’s motion to bar the opinion of plaintiff’s expert as a “net opinion” and granted summary judgment in favor of defendant.

The appellate court affirmed the trial court’s exclusion of the expert opinion concerning plaintiff’s design defect claim. However, it reversed the court’s rejection of the expert’s proposed testimony on the issues of manufacturing defect and negligent installation. The appellate court opined that plaintiff’s expert considered a variety of sources including investigative records, the parties’ discovery responses, and photographs. Plaintiff’s expert also visually examined the grip handle that had detached from the trailer.

The appellate court concluded that plaintiff’s expert sufficiently and reasonably explained the physical deficiencies showing the rivets were improperly installed on the grip handle and trailer in an unsafe manner through review of the physical evidence and examination of the grip handle.

Attorneys must pay particular attention to the opinions and both their own expert witnesses and those of opposing counsel due to the key role expert witnesses play in establishing or contesting a claim for damages and liability. A careful review of expert reports to ensure that the conclusion are not based on a net opinion could prevent controversy during the course of litigation.  Thanks to Steve Kim for his contribution to this post.  Please email Brian Gibbons with any questions.