I wouldn't tell my players to let up, either. But there are other things that a coach can do, such as giving most of the ice time to his second, third, and fourth (if he has one) lines after the game has, for all intents and purposes, been decided. That gives his third and fourth (if he has one) lines some extra PT, perhaps saves the opponent from feeling that they were mercilessly (and needlessly) pounded into the ground, and preserves the coach's reputation. Devils Lake was only beaten 5-0 by both West Fargo and Grand Forks, so, on the surface at least, 18-0 looks like a needless beatdown.