What is the central idea of the following paragraph?
During a baseball game, Tanner tried to tag a player leaving first base. When the umpire called the player out, Tanner immediately informed the umpire that he in fact did not tag the runner. Two weeks later, the very same umpire was at another one of Tanner’s baseball games. Tanner was playing short stop and tagged a runner as they approached third base. When the umpire called the player safe, Tanner didn’t say a word, but the umpire noticed the surprised look on Tanner’s face. “Did you tag the runner?” she asked Tanner. When Tanner told her that he did tag the runner, the umpire changed her decision and called the player out. The coaches and parents were furious, but the umpire stood by her decision.