25.1 (8) Justification for acts or omissions
A public officer is justified in committing an act or omission — or in directing the commission of an act or omission under subsection (10) — that would otherwise constitute an offence if the public officer
(a) is engaged in the investigation of an offence under, or the enforcement of, an Act of Parliament or in the investigation of criminal activity;
(b) is designated under subsection (3) or (6); and
(c) believes on reasonable grounds that the commission of the act or omission, as compared to the nature of the offence or criminal activity being investigated, is reasonable and proportional in the circumstances, having regard to such matters as the nature of the act or omission, the nature of the investigation and the reasonable availability of other means for carrying out the public officer’s law enforcement duties.