N sued H for defamation. H then applied to have N’s defamation action British Columbia’s Protection of Public Participation Act (“PPPA”). The chambers judge allowed the application and dismissed the action. He held both that H had a valid fair comment defence and that the value in protecting his expression outweighed the resulting harm done to N. The Court of Appeal disagreed on both counts and reinstated the action. Held (Côté J. dissenting): The appeal should be allowed. Per Wagner C.J. and Karakatsanis, Rowe, Martin, Jamal and O’Bonsawin JJ.: The chambers judge did not err in concluding that the public interest weighing exercise mandated dismissal of the underlying action or that N failed to adequately challenge the validity of H’s fair comment defence. Accordingly, his order dismissing the defamation action should be restored. Section 4 of the PPPA creates a pretrial screening mechanism that instructs a judge to dismiss an action arising from expression on a matter of public interest unless the plaintiff can satisfy the judge that their action has substantial merit (s. 4(2)(a)(i)); the defendant has no valid defence in the proceeding (s. 4(2)(a)(ii)); and the harm to the plaintiff as a result of the defendant’s expression is serious enough to outweigh the public interest in protecting that expression (s. 4(2)(b)). A s. 4 application first requires the defendant to prove that the proceeding arises from expression that relates to a matter of public interest (s. 4(1)), at which point the onus shifts to the plaintiff under s. 4(2). 2023 SCC 14 (CanLII) dismissed as a strategic lawsuit against public participation (“SLAPP”) under s. 4 of