Well, LMGTFY, since it's beyond your understanding: 
http://ottawacitizen.com/news/local-news/ottawa-man-not-guilty-because-he-thought-he-could-have-sex-with-wife-anytime

His wife alleged that, in 2002, he grabbed her by the wrist, pulled her onto the couch, pulled down her pants and had sex with her even though she asked him three times to stop.

The judge said she was a credible witness who gave straightforward answers.

Court heard that at the time, in 2002, the husband had undergone a hair transplant. His doctor, he testified, had told him to abstain from sex for two weeks after the surgical procedure. He told court the alleged incident could not have happened because he had followed that advice.

“The accused did not call any medical evidence to show this was standard medical practice,” the judge said, “and I find his evidence in this regard does not accord with common sense to a reasonably informed person.”