I knew this sort of thing happened but this is the first time I have heard it used as a defense in a sexual assault case:

TORONTO – In an unusual case Tuesday in a Toronto courtroom, a 33-year-old man was acquitted of sexual assault after a judge ruled he was asleep during the attack, the Toronto Sun reported Wednesday.

“This is indeed a rare case,” said Justice Russell Otter, as the woman who Jan Luedecke had sex with shook, sobbed and then left the courtroom.

“His conduct was not voluntary.”

…

Luedecke, a landscaper, met the woman at a party on July 6, 2003. Both had been drinking.

The woman had fallen asleep on a couch. She woke up to find him having sex with her. She pushed him off, then contacted the police.

Luedecke said he fell asleep on the same couch and woke up when he was thrown to the floor.

He only suspected he had had sex after using the bathroom and discovering he was wearing a condom, court heard. He confessed to police.

During his trial, sleep expert Dr. Colin Shapiro testified Luedecke had parasomnia – a disorder with symptoms such as sleep-walking. Shapiro testified Luedecke suffered from sexsomnia, which is sexual behavior during sleep.

It was brought on by alcohol, sleep deprivation and genetics, Shapiro said.

Luedecke previously had sex while asleep with four girlfriends, court heard.

News of the successful defence of sexsomnia may spread to others accused of sexual assault, said University of Toronto law professor Hamish Stewart.

“We may hear more forms of this defence from accused persons,” he said, adding he has never previously heard of such a case.

Luedecke has cut down on his drinking and is taking medication to stop a repeat of the incident, court heard.

It sounds to me like the correct decision was reached but the woman says she has the means and the intent to appeal the decision.  I would like to suggest she stop falling asleep in drunk stupors at parties and get on with her life.