The reason the decision is so controversial is because it was done so close to deadline, there's no way the G's would have had enough time to change their vote to try to save X. If it had been done earlier today, it would have been more straightforward, to autolynch j0ker AND lynch another player. But his stunt was unfair to one side of the game, even though by the book Sam made the right choice (if a player reveals his role, he's out, but someone else still gets lynched that day, much like what happened with Fr3sh).
The modification to the rule should go something like this: If you cheat in any way, whether it's to gain an advantage or to get yourself purposely autolynched because you're bored or butthurt or whatever, it's an auto-ban from this game and all subsequent games unless a certain number of people vote to let you back in. Stricter approach will discourage people from pulling shit like that.
And cheating includes revealing your role through posting the PM screenshot, giving out your password, making double accounts to get info or trick people, etc.