Since so many people are cheating and gamethrowing, why not add a Cheater and Gamethrower role? You would have them appear as a normal role to everyone else, but only they can see they're a Cheater or Gamethrower, and the way they would win is by gamethrowing on their pretend role, and having someone report them. Moderators can check the replay and watch it as the player to see they were a "Gamethrower", then update the game to award them their points