Unable to predict whether the Pennsylvania Supreme Court would hold Amazon strictly liable for a third-party vendor's defective product, the U.S. Court of Appeals for the Third Circuit has sent the case to the state high court, asking it to weigh in.

The court's decision came in the case of Oberdorf v. Amazon.com, in which the plaintiff was injured when a dog leash, purchased on Amazon, broke and hit her in the face. The central question in case was whether the Restatement (Second) of Torts Section 402A applies to Amazon.

"This is an issue of first impression and substantial public importance, yet we cannot discern if and how Section 402A applies to Amazon. We are, as a result, unable to predict how the Pennsylvania Supreme Court would rule in this dispute," Chief Judge D. Brooks Smith wrote in the court's order.

The ruling comes after the Third Circuit reheard the case en banc. Prior to that, the a split court ruled 2-1 that Amazon could be held liable.

Amazon had argued that, under the test outlined in a 1989 Pennsylvania Supreme Court decision, it could not be held liable as a "seller," but Senior Judge Jane Richards Roth, who wrote the Third Circuit's July majority opinion, determined that because the company was in a position to prevent the circulation of defective products and because imposing liability would incentivize safety that test weighed more in favor of designating the company as a "seller" under 402A.

"Amazon's customers are particularly vulnerable in situations like the present case," Roth said. "Neither the [plaintiffs] nor Amazon has been able to locate the third-party vendor, The Furry Gang. Conversely, had there been an incentive for Amazon to keep track of its third-party vendors, it might have done so."

The ruling bucked a recent trend where both the Fourth and Sixth circuits held that the company could not be liable as a seller under state products liability laws.

In its request to have the initial ruling reconsidered, Amazon contended that the ruling conflicted with other districts and argued the appeal judges had been acting as "judicial pioneers," establishing a precedent with "no practical limit."

"The majority's decision 'substantially widen[s]' the scope of liability for online stores and marketplaces operating in Pennsylvania, including Amazon, eBay, Walmart Marketplace, and smaller businesses like Etsy, Bonanza, and Jet," Amazon said in its petition.

David Wilk of Lepley, Engelman, Yaw & Wilk in Williamsport represents the plaintiff.

"Based on the amount of time the en banc panel spent on the issue during the oral argument in February, it really comes as no surprise that the court went in this direction," he said. "We look forward to presenting our arguments to the Pennsylvania Supreme Court."

Perkins Coie attorney Brendan Murphy, who is representing Amazon, did not respond to a request for comment.