My uncle was "put on leave" for separating 2 boys fighting - the whole physical contact thing. He quit teaching; and he was an awesome teacher; said he'd had enough of the garbage that he as a teacher had to put up with.
I have physically intervened when I knew the teacher couldn't. My son (6 at the time) was playing and the thug bully in his class wouldn't leave him alone. Mitch tried all the reasoning; talking, tell someone stuff; even took a fall so the teacher could see; but the little brat wouldn't stop punching, pushing; etc. Mitchie is a real mellow kid; with a great heart; so I wasn't going to stand for that; and wasn't going to rely on the old adage of standing up for yourself.
I was watching and finally they were lined up by the fence; knapsacks on and the kid moves in line so can stand behind Mitch and push and shove some more. Not on my watch, buster! I leaned over the fence; picked up the little jerk by his knapsack straps and growled at him - You see that kid there - pointed at Mitch - he's mine; everything about him is mine; and I don't like nobody touching my stuff; so you'd best keep your hands to yourself - rolling eyes from the thug -- Understand - nodded assent; dropped him to his feet and stepped back. Nodded at Mitch and waited. Kids all went home or to daycare and the teacher approached me and thanked me.
Since then, little thug boy has waffled between being Mitch's friend and ignoring him; but no more physical contact.
My best friend dealt with her boy in a cute way; gr. 8/9 he was informed about children's rights and came home and announced to his mother that she couldn't discipline him physically anymore; and if she yelled at him; it was mental stress; verbal abuse (i know this kid; if he ever got more than 3 whacks in his life it would be amazing); so she turned to him and said; Yes son, I understand; if you feel I've been unfair or abusive to you; here is the number for Family and Children's Services; we'll pack your bags and have them pick you up; but I'm keeping your ATV, your toys, clothes, video games, movies, CDs; etc.; since you haven't paid for them; they are technically mine and they will stay at the house when you leave.
Never another peep out of him about the topic!