Case comment: A critique of the Supreme Court of Canada's use of statistical reasoning in R v. Mabior

Abstract

This case comment critiques the Supreme Court of Canada's decision in R v. Mabior. In Mabior, Chief Justice McLachlin affirmed the criminalization of human immunodeficiency virus (HIV) nondisclosure to sexual partners, and sought to clarify exactly when criminal sanctions apply. Citing expert evidence, McLachlin CJC held that criminal liability is appropriate for HIV non-disclosure when there is a 'realistic possibility of transmission' and that only condomuse combinedwith antiretroviral therapy reduces this risk enough to preclude liability. Using the same expert evidence, I calculate the transmission rates underlying this argument and showthatMcLachlin CJC's use of statistics results in logical contradictions and uncertain liability. I argue that her statistical approach is unworkable and I propose an alternative non-disclosure regime.