Products Liability Law Daily Wrap Up, DESIGN AND MANUFACTURING DEFECTS—HOUSEHOLD PRODUCTS—D. Mass.: Mason jar injury suit dismissed after expert excluded and plaintiff fails to prove defect, (Sep 2, 2026)

By Susan Smith, J.D., M.A.

A plaintiff alleging injuries from a shattered mason jar failed to present admissible evidence of a product defect after the court excluded his expert's opinions as speculative.

A plaintiff who alleged that a Ball Widemouth Quart Jar shattered and injured his hand could not proceed on negligence, breach of warranty, or Massachusetts consumer protection claims because he failed to present admissible evidence that the jar was defective. After excluding the plaintiff's expert testimony as speculative, the federal district court granted summary judgment to Walmart Inc. and Rubbermaid Inc. (New v. Rubbermaid Inc., No. 24-11277-BEM (D. Mass. Aug. 31, 2026)).

Background. The plaintiff purchased a package of Ball Widemouth Quart Jars from a Walmart store in Massachusetts. The jars were not visibly broken when purchased. He placed the package in a kitchen cabinet and did not access the jars again for more than five weeks. The parties disputed whether the jar broke while the plaintiff was attempting to open it or whether he cut himself on the jar while swatting at an ant. An emergency department record stated that the plaintiff reported cutting his hand on a canning jar while washing dishes and swatting at an ant. The subject jar was discarded after the incident.

The plaintiff filed suit alleging negligence, breach of warranty, and violations of Massachusetts General Laws Chapter 93A against Walmart and Rubbermaid.

Expert testimony excluded. To support his claims, the plaintiff relied on an engineering expert who opined that residual internal stresses, physical defects, or damage occurring during transport may have contributed to the jar's failure. However, the expert acknowledged that he never examined the subject jar because it had been discarded and did not inspect the remaining jars from the package. He further conceded that the precise defect could not be identified.

The court found that the expert's opinions were based largely on the plaintiff's account of the incident and general scientific principles rather than testing, scientific data, literature, or information regarding how the jars had been handled or transported. The court concluded that the opinions amounted to speculative hypotheses rather than reliable expert analysis and therefore did not satisfy the standards for admissibility.

The court also declined to consider a declaration submitted by the expert after the expert-disclosure deadline that attempted to offer more definitive opinions regarding the cause of the jar's failure.

Breach of warranty. The court explained that a plaintiff pursuing a breach of warranty claim must present evidence of a product defect. Without admissible expert testimony, the plaintiff lacked evidence that the jar was defective when it left the defendants' control.

The plaintiff alternatively relied on a res ipsa loquitur theory, arguing that the occurrence itself permitted an inference of defect. The court rejected that argument, noting that the theory was raised for the first time in opposition to summary judgment after discovery had closed. The court further held that, even if the theory were properly before it, the plaintiff failed to eliminate himself as a potential cause of the injury. Evidence in the record, including the emergency department report and the expert's acknowledgment that post-purchase handling, temperature variations, or glass-to-glass contact could have contributed to the failure, prevented such an inference. The court therefore granted Walmart summary judgment on the breach of warranty claim.

Negligence. The negligence claim failed for the same reason. Because the plaintiff failed to present sufficient evidence of a defect, he could not establish negligence. The court noted that where there is no basis for warranty liability arising from a defective product, a negligence claim likewise cannot succeed.

Chapter 93A. The court also dismissed the plaintiff's Chapter 93A claim. Because the consumer protection claim was wholly derivative of the failed product liability claims and the plaintiff alleged no independent unfair or deceptive conduct, summary judgment was warranted on that count as well.

Rubbermaid. The court granted summary judgment to Rubbermaid on all counts for substantially the same reasons that supported judgment in Walmart's favor.

The case is No. 24-11277-BEM.

Judge: Murphy, B. E.

Attorneys: John D. McCoy (Law Office of John D. McCoy) for William New. Holly M. Polglase (Shook, Hardy & Bacon LLP) for Rubbermaid Inc.

Companies: Rubbermaid Inc.

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