Gets worse and maybe more complicated.
Ref is already up on charges for assaulting a chick while working security at a north shore pub.
Having said that, the boxer came charging at him and he hit him. Reckon the boxer is within his rights to drop him. But to continue to go to town on him and boot him in the face while down - thats excessive force (especially if he's a boxer).
Cannot see old mate getting off on self defence. That ended when the ref was on the ground. But you're right. Does change the narrative.