In Bosco v Mentor Worldwide LLC, 2024 BCSC 1931, the B.C. Supreme Court declined to certify certain common issues due to flaws in the plaintiffs’ evidence. The court found the plaintiffs had failed to provide evidence that there was ‘some basis in fact’ for the actual harm or materialized loss caused by the defendants’ alleged negligence.

Background

Bosco is a proposed class action on behalf of Canadians who received the defendants’ silicone breast implants. The plaintiffs allege that the breast implants cause or contribute to adverse health effects.

Some contested common issues related to alleged inadequate disclosure of the presence of heavy metals and other volatile chemicals (“toxins”) in the implants, and whether this failure to disclose was negligent and/or in breach of consumer protection and competition legislation. The plaintiffs claim that the alleged toxins can diffuse through the shell of the implants causing harmful health effects and claim to have evidence that more than 1,000 class members suffered adverse health impacts from the implants.

The defendants argued there was no evidence to suggest any alleged toxins are present in the implants in quantities that would cause harmful health effects or that class members had been diagnosed with any adverse health effect caused by the alleged toxins.

Evidence at Certification Must be Admissible

The court declined to certify the proposed common issues related to the  alleged toxins: there was not enough evidence to show any basis in fact that the alleged toxins were present in or diffused from the implants in sufficient quantities to cause harm.

In particular, the plaintiffs sought to admit an expert report on the presence of platinum in the implants by a doctor who had admittedly “never conducted any research or published any scientific papers about platinum” (para. 116). Nor did the doctor opine on any other of the alleged toxins in his report. The court found the proposed expert could not offer expert opinion evidence on platinum or any other alleged toxins.

The plaintiffs also relied on a document published by the United States Food and Drug Administration (“FDA”) containing non-binding recommendations on the format and content for labelling information for manufacturers of breast implants. The court held the document was admissible only to show that the FDA made these requirements and that the defendants did not follow them. The FDA guidance was not admissible to show that any of the alleged toxins could actually cause adverse health effects.

The plaintiffs also tendered the results of hair element analyses conducted on an anonymous class member’s hair that purported to show a reduction in toxins after the removal of her implants. The court accepted this evidence only to show that individual had performed those tests and received those results. However, because there was no qualified expert to interpret those test results, the court placed little weight on them.

The plaintiffs also provided affidavit evidence of their own experiences with breast implants, noting that they suffered actual injury after their breast implant surgery, and that those who had their implants removed enjoyed improvement in their symptoms thereafter. However, these affidavits provided no evidence of specific risks or harms, and therefore did not assist the plaintiffs in establishing that the defendant owed a duty to warn.

Takeaways

Bosco provides three key takeaways for litigants at certification:

(1) Admissibility of Evidence

The plaintiff must rely on admissible evidence to establish ‘some basis in fact’ to support the common issues. While the ‘some basis in fact’ test is a lower threshold than proof at trial, this lower threshold does not affect the admissibility of evidence. Instead, the rules of evidence and the usual criteria for admissibility apply on certification applications.

(2) Expert Evidence

Experts will be qualified to give expert opinion evidence only in their areas of expertise, and their evidence must be sufficiently reliable to provide some basis in fact to support the common issues. Expert evidence can be attacked where the expert purports to give evidence outside their areas of expertise.

In addition, technical evidence, like the hair element analyses in this case done by a non-expert, can be challenged where there is no expert report to provide an opinion on the evidence.

(3) Negligent Failure to Warn

Where a plaintiff alleges negligent failure to warn in a class action, the issue will be certified only where the plaintiff provides admissible evidence that class members suffered some actual harm or materialized loss. A defendant is not under a duty to warn of general, potential harms.