The Crown then took the case to the Supreme Court of Canada, which upheld the appeal decision because the jury didn't have a chance to consider the defence that Esau had an "honest but mistaken belief in consent." The ruling was split on gender lines, however, with five male judges ruling in Esau's favor, and the two female members arguing against him.

Following are excerpts from the decision, which is being examined closely by Northern lawyers who deal frequently with sexual assault cases involving consent issues.

The majority decision:

"Before a court should consider the defence of honest but mistaken belief or instruct a jury on it there must be some plausible evidence in support so as to give an air of reality to the defence. Here, the plausible evidence comes from the testimony of the complainant and the accused and the surrounding circumstances of the alleged sexual assault.

The accused's evidence amounted to more than a bare assertion of belief in consent. He described specific words and actions on the part of the complainant that led him to believe that she was consenting. This alone may be enough to raise the defence, but there was more.

The complainant's evidence did not contradict that of the accused, as she cannot remember what occurred after she went to her bedroom. In addition there was no evidence of violence, struggle or force....

The complainant did not testify that she did not in fact consent, but was only able to say that because she was related to the accused, she would not have consented. The accused's evidence of the complainant's participatory actions, if believed, might lead a jury to conclude that he honestly believed she was consenting despite his being mistaken about her ability to legally consent because of intoxication. This meets the threshold of a plausible explanation of the facts and should have been put to the jury...."

While passivity by the complainant may not be consent, her absence of memory has to be considered with the evidence of the accused that the complainant seemed to participate willingly."

Dissenting opinion (Justice McLachlin):

"... an accused cannot raise the defence of mistaken belief in consent if he did not take 'reasonable steps ... to ascertain that the complainant was consenting. In this case, where the complainant was on any view of the evidence quite drunk, the absence of any evidence of steps taken by the accused to ascertain consent precludes him from raising the defence....

The accused cannot have been wilfully blind or reckless. An accused is not entitled to presume consent in the absence of communicative ability and thus cannot raise the defence in the case of an unconscious or incoherent complainant. Passivity without more is also insufficient to provide a basis for the defence....

If the accused wrongly inferred clear capacity and an active communication of consent from lack of struggle or passivity, he must have been either wilfully blind or dishonest."

Dissenting opinion (Justice L'Heureux-Dubé):

"The traditional common-law understanding of lack of consent... should be changed. The customary focus on the complainant's communication of refusal or rejection of the sexual touching in question should be rejected in favor of an assessment of whether and how the accused ascertained that the complainant was consenting to such activity....

Where an accused has demonstrated that he honestly, with some basis in the circumstances, misperceived these indicators, and therefore lacked the necessary culpable mind, the defence of honest but mistaken belief may arise. Here, there was no evidentiary basis for ambiguous communication on the part of the complainant or external circumstances which could have influenced the perceptions of the accused."