Background: The respondents initiated the action in January 2019 under the Class Proceedings Act, alleging defects in Mentor Breast Implants. They claimed the appellants, Mentor Worldwide LLC and Johnson & Johnson Inc., failed to test adequately and warn users of risks such as anaplastic large cell lymphoma (BIA-ALCL), connective tissue disease (CTD), and autoimmune/inflammatory syndrome (ASIA/BII). They sought class action certification for all Canadians implanted with Mentor Breast Implants since October 19, 2006. The proposed representative plaintiffs submitted affidavits describing health issues post-implantation.

Legal Arguments/Issues: The appellants challenged the dismissal of their application for the respondents’ medical records before the certification hearing, arguing the records were necessary to inform certification issues. They claimed the judge misapplied the test for document production and failed to consider expert evidence. The respondents argued that pre-certification production of medical records was unnecessary and would derail the certification process into individual claim merits.

Court's Decision: The Court of Appeal dismissed the appeal, upholding the chambers judge's decision. It ruled that the production of medical records was not necessary for the certification process, emphasizing that the certification stage assesses procedural suitability rather than the case's merits. The judge did not err in her discretion, as requiring the records would have improperly shifted focus to individual claims.

Costs/Damages Awarded: The decision did not specify the amount of costs or damages awarded to the successful party within the provided document excerpt. The focus remained on procedural appropriateness rather than financial awards.