Image copyright Getty Images Image caption Canadian law does not directly define how drunk is too drunk to consent to sex

A Canadian judge's finding that "clearly a drunk can consent", as he cleared a cab driver of sexual assault, has drawn legal criticism.

Nova Scotia Justice Gregory Lenehan found Bassam al-Rawi not guilty of sexual assault on Wednesday.

Police discovered Mr al-Rawi, 40, with an unconscious naked female passenger in his taxi in Halifax on 23 May 2015.

The unnamed 26-year-old's blood-alcohol level was three times the legal limit, and she had urinated on herself.

The woman got into Mr al-Rawi's cab at about 01:09 local time, the court heard.

Police who were reportedly responding to separate incident in the area noticed her in the cab at 01:20.

She was unconscious and naked from the chest down.

Mr al-Rawi was also found semi-clothed. Her DNA was found on his person.

In his ruling, Justice Lenehan said that just because the accuser was drunk it did not mean she was incapable of consent.

"A person would be incapable of giving consent if she is unconscious or is so intoxicated by alcohol or drugs as to be incapable of understanding or perceiving the situation that presents itself," Justice Lenehan said, according to a transcript of his oral decision published in the National Post.

"This does not mean, however, that an intoxicated person cannot give consent to sexual activity. Clearly, a drunk can consent."

That interpretation of the law has some legal experts worried.

Canadian law says that a person cannot consent to sex while unconscious.

But it does not directly define how drunk is too drunk to consent to sex.

The law does say an extremely drunk person can be conscious but too drunk to consent.

A person must be sober enough to understand the sexual nature of the act, and to realise they can choose not to participate.

"Where is the line between capacity and incapacity when it comes to consent?" asked Elizabeth Sheehy, a law professor at the University of Ottawa.

"Surely, the line is crossed sometime before someone is actually unconscious."

Prof Sheehy told the BBC that she takes issue with the judge's narrow understanding of what it means to be incapable of consent.

It took only 11 minutes for the woman to go from hailing a cab and texting her friends to being passed out, according to police.

"It's kind of hard to believe that she was capable of consent in that very small window," Prof Sheehy said.

The academic noted the woman's blood-alcohol level.

Dalhousie University law professor Elaine Brooks Craig also said the judge's ruling raises concern, although it is difficult to draw firm conclusions without reading the full trial transcript.

Image caption Legal experts Elizabeth Sheehy (l) and Elaine Brooks Craig (r)

Justice Lenehan's statement that "clearly a drunk can consent" is especially "concerning", Prof Craig told the BBC.

"Think about what it means to have that line repeated, headline after headline, around the battle that is going on in university campuses around sexual assault and consent," she said.

CBC reported that the judiciary committee has received at least 10 complaints about Justice Lenehan, but that provincial court matters are out of its jurisdiction. The prosecution said it will review his ruling before deciding whether to appeal.

This is not the first time questions have been raised about how a Canadian court interprets sexual consent.

Alberta Justice Robin Camp could find himself removed from the bench after he questioned why a sex-assault complainant did not "keep (her) knees together".