There was a push from Hogan in the chest of Woking's Number 4, but Collar's push was more 'violent' and only deemed worthy of a yellow, so why Hogan got a red I've no idea. The rest of the time he was trying to diffuse the melee. The 4th official was incompetent and has seen something which wasn't there.
(Woking's No.4 was a tw@t all game, always in the ref's ear).