Referees and/or officials from college or high-school ranks that take the place of the regular referees in all major sports, mostly when they've gone on strike or are locked out. Notorious for blowing calls and forgetting things like timeouts or which down it is. A good example of this is the replacement officials calling NFL games, who have come under serious fire by the coaches, fans, and players alike.
The Packers lost because the rent-a-refs made some bad calls late in the game.