Case in point: when I was younger and played soccer, we had one ref who before the game would go over rules with us. Invariably, he'd ask us what offsides was. A younger kid would always give him the book answer for the league: being ahead of the ball with less than two defenders between you and the goal (goalie counts as one). He'd quickly then say "no! offsides is this." and point to his whistle. The point was very clear... He had the final call on what was offsides, so there was no use complaining if we had a different opinion.
Yep, as anyone who watched the World Cup learned: see the phantom foul (no one even knows who it was allegedly on) that took away the US victory over Slovenia, or the referee denying a game-tying goal by England against Germany that the whole stadium got to see on replay, to which FIFA's response was to ban replay from the rest of the World Cup.
It's not good in sports and it's far worse in government.