If they're whistle-happy, they can slow the pace. Neither team can find a rhythm when the officials are calling a foul on every possession. If an official overrules another official, this may mean that the first official thinks he is bigger than the game.
Some teams play more physically than others.
An underdog fights this problem, especially on the road. In a close call, many times, the call favors the team that the official believes is supposed to be the better team. In the NBA, this call is known as star treatment or, more recently, Jordan rules. Finding an official who will call a sixth foul on Michael Jordan in the United Center is as easy as shaving with a spoon. The best officials are the ones you don't know or don't remember.