In Barrett's case, Hodgman spilled a pass as he headed into the tackle and, with the ball gone, Barrett connected with the head while making no attempt to wrap his right arm.
Hodgman stayed down to receive attention and, after a quick consultation with TMO Aaron Paterson, referee Mike Fraser showed the Crusaders captain a red card as the home fans booed.
Commentator Justin Marshall said Barrett was "going to be in big trouble" since the hit was late and collected Hodgman "flush on the jaw".
"There's nothing mitigating it," Marshall said. "I don't think there was any intent, but the way it transpired, it was late and he didn't do enough to avoid the collision."