The large-scale breathing machine recall that led to over a billion dollars worth of legal settlements was premised on significantly flawed third-party research, the machines’ manufacturer alleged in a recently filed lawsuit.

In a complaint, Philips alleged that PSN Labs LLC, which Philips had hired to study the sound abatement foam used in some of its sleep and respiratory care devices, incorrectly concluded that the product contained dangerous levels of potentially cancer-causing substances. This prompted Philips to initiate a recall of over 15 million devices globally.