Guilty until proven innocent eh? I've been accused of crimes that I didn't commit and had to go to court and trial to fight... how do we know he wasn't falsely accused?
That's the problem with crimes without witnesses. It's your word against mine, and the world is full of people who commit these crimes but also full of people who, knowing that this is the situation, will falsely accuse others of them. Without major privacy violations becoming the norm, it's a pickle I don't really see a way out of: somebody will continue to get the short end of the stick.