The referees that officiate the Stanley Cup Finals are supposed to be the best in the world. They're supposed to be the best the business has to offer. Unfortunately for tonight's officiating crew fell for the oldest trick in the book.
As Anthony Cirelli made a play for the puck, Cale Makar easily goes down. At the time no referee's arm goes up, but the Colorado immediately erupts in a chorus of boos. It's at that point the referee lifts his arm and calls a penalty.
Cirelli was given 2-minutes for tripping on the play. Colorado would score on the powerplay giving them a 3-1 lead at the time.