If you watch the replay you see Anderson signal a goal then changed his mind and awarded the penalty shot instead. Yes we'd have gone on the Power Play for tripping if Kristo Scores. The reason Kristo doesn't get the goal was it was not an imminent goal situation. Had the Denver goalie not been on the ice (doesn't need to be in net) and Kristo is fouled from behind then Anderson would have had to award a goal instead of an empty net penalty shot.