My children wouldn't wear mohawks without their dad beating the crap out of them. I seriously question the judgement of the parents.
That said, this sounds like more of public screwls forcing their way in to be surrogate parents.
I think the school caused more of a disturbance by their actions.
Of course, when I was in jr high, and a girlfriend and I dyed our hair hotpink and cut arm holes in hefty bags and wore those as shirts, they sent us home also.
If the school had left him alone, the classmates would have been over this in oh, a day or so.