This article discusses the concept of personal stare decisis and the issue of horizontal precedent through examination of Canada's jurisprudence on the (over) criminalization of HIV non-disclosure. The Court's reasoning in R v Cuerrier and R v Mabior, as well as the trial decisions decided since Mabior are examined. The point is not to suggest that Justice McLachlin’s approach in Cuerrier offered the perfect solution to this issue. Indeed, as Isabel Grant argues, a better approach would remove non-disclosure of HIV status from the sexual assault criminal law regime and in its stead reintroduce the use of offences such as nuisance and criminal negligence. Rather, the point is to suggest that what Chief Justice McLachlin did in Mabior was to uphold a deeply problematic legal regime and in the process overturn herself, without explanation, on nearly every single principled objection to this regime that she had previously made.