McRuer was a central figure in the post-WWII civil liberties movement.  He was Chief Justice of Ontario when the federal Bill of Rights was passed and he chaired the Ontario Royal Commission on Civil Rights that led to the most significant overhaul of statutes in Ontario history, designed to better protect individual rights.  In addition to recommending a bill of rights for Ontario, the McRuer commission recommended an amendment to the Public Inquiries Act that would ensure witnesses access to legal counsel when speaking before a government inquiry.   Patrick Boyer has written an excellent biography of McRuer.

"McRuer was the first judge to reject a motion to have the espionage commission's transcripts ruled inadmissible in Rex v Mazerall; he concluded that witnesses should specifically demand protection under the Canada Evidence Act in order to avoid self-incrimination. He argued that the purpose of the statute was to ensure statements made before a government tribunal or court were truthful; if the witness failed to request privilege, it could be assumed that their statements were voluntary and true. Ignorance of the law, McRuer pointed out, was not a defence. The Ontario Court of Appeal upheld McRuer’s decision and concluded that truthfulness was a matter for the jury to decide. This decision was then cited by judges who came to similar conclusions in the trials of Gordon Lunan, Raymond Boyer and Durnford Smith. Judge McRuer concluded that he was “not at all clear that this court has, in these proceedings, any jurisdiction to review the conduct of the commission or to decide that a commission acting with apparent lawful jurisdiction has at any time by its conduct deprived itself of jurisdiction.” [Source: Dominique Clément, “The Royal Commission on Espionage and the Spy Trials of 1946-9: A Case Study in Parliamentary Supremacy" Journal of the Canadian Historical Association (2000): 151-172.]