In addition to bets on which team will win by what point spread, there are over under bets on the total number of points scored, bets on individual quarters and halves, and sometimes bets on individual player performances. Since an official cheating to assist gambling doesn’t necessarily involve who wins, or even the point spread, it’s easy to see how Donaghy was able to get away with it for a while. In retrospect patterns may be visible, but in real time who is going to really notice that one or the other or both teams is over the limit for team fouls early in the quarter? By calling a lot of fouls early, putting both teams over the limit for team fouls, a referee can increase the odds that the score will be high, affecting over/under bets.
One of the reasons why a crooked ref can get away with it is that professional leagues don’t always follow the rule book to the letter of the law, allowing some discretion to the official. I doubt any Major League Baseball umpires call the strike zone exactly how it is in the rule book. The NBA threw away the rule book on traveling for Michael Jordan. When I see kids and teens playing basketball I always ask them how many steps can you take driving to the basket and none of them know. NHL refs are notorious for “putting away the whistle” and “letting them play”, at the end of close playoff games.
