Other mistake: When Roy is about to hit the ball off the porta-potty, the TV commentator bets Romeo that he won't hit the shot onto the green. Roy's shot ends up on the fringe of the green, not on the putting surface itself (an important difference), but Dewey collects the bet.
Other mistake: When Roy makes the bet with Gary McCord on his second shot of the bathroom wall, the bet was he would get the bounce shot onto the green. The ball never gets on the green. The ball is actually on the fringe and a good 5 feet away from the green. Yet Gary still pays the bet that he lost. In reality he won the bet.