Cheating is not analogous, in that case you have an impartial professor or proctor making a clear determination on what should be clear evidence of a misdeed of a non-criminal nature. Unless you have a credible witness to an alleged rape or other sexual misconduct it often comes down to a case of "he said, she said". In any case,  rape being the serious charge that it is, demands more than that before it is hung around the neck of the accused. It's a matter for the justice system to decide, not academic institutions.