Federal Court Addresses Scope of Permissible Liability Expert Testimony in a Products Liability Case

In the case of Borden v. Mainline Conveyor Systems, Inc., No. 4:23-CV-01486 (M.D. Pa. July 21, 2025 Mehalchick, J.), the court addressed Motions In Limine filed by a Plaintiff in a products liability case that sought, in part, to preclude certain testimony by a defense engineering expert.

According to the Opinion, the Plaintiff was working for a container company when he stepped on a mesh belt conveyor that activated and threw him off, resulting in injuries. 

The Plaintiff sued the conveyor belt manufacturer, claiming that the company was strictly liable for manufacturing a defective and unreasonably dangerous device.

The court otherwise rejected the Plaintiff’s Motion In Limine to preclude the defense from pursuing an assumption of risk defense. 

Here, the court found that there were issues of fact regarding whether or not the Plaintiff was required by his employer to walk over the conveyor belt and whether the Plaintiff was aware of the risk that the conveyor belt would be inadvertently activated. Given these issues of fact, the defense was permitted to proceed with its assumption of the risk defense.

In her Opinion, Judge Mehalchick limited the Defendant’s liability expert’s opinion and ruled that the defense expert would not be permitted to testify regarding the import of a contract between certain parties relative to the machine at issue, in terms of which company was responsible for certain actions. The court found that such testimony would be impermissible interpretation of a contract by the expert rather than the offering of an opinion on customs and practices within the conveyor manufacturing industry.

Anyone wishing to review a copy of this decision may click this LINK.


Source: Article: “Engineering Expert’s Testimony Improperly Waded Into Contract, Pa. Fed. Judge Rules In Products Liability Dispute,” By Riley Brennan of the Legal Intelligencer (July 21, 2025).

Expert Not Permitted to Testify as to the Requirements of the Law

In the case of Major v. Five Star Equipment, Inc., No. 2020-CV-3550 (C.P. Lacka. Co. Nov. 15, 2024 Nealon, J.), Judge Terrence R. Nealon of the Lackawanna County Court of Common Pleas addressed the extent to which an accident reconstruction expert could comment on the applicable law at trial in a motor vehicle accident case.

In addressing this issue, Judge Nealon provided a thorough review of the current status of the law regarding pedestrians crossing roadways in Pennsylvania. 

Relative to the particular issue in question, the court ruled that it is well settled that an expert is not permitted to give an opinion on a question of law and that, therefore, an expert witness may not be offered to testify as to the governing law or what the law required.

As such, in this case, the Plaintiff’s accident reconstruction expert was prohibited from providing testimony or expressing any opinion regarding the governing law pertaining to the duties of pedestrian and motorists at intersections or within crosswalks.

Anyone wishing to review a copy of this decision may click this LINK.

Source of image:  Photo by Vinta Supply Co. NYC on www.pexels.com.