I don't have anything to add, as Grinity and DeeDee and everyone has comprehensively covered everything I might have said, but I just wanted to let you know that I totally understand where you're coming from! Including "earlier than usual", LOL!
DS9 hasn't (knock on wood) had any "bully slips" so far this year, but I'm sure we'll get some eventually. He is 2E with Asperger's and prone to just the sort of incident your DS just had. It sounds like your school just isn't handling it properly, and I'm sorry for that. Our school gives him the same "bully slip" or "pink slip" that any other kid would get, but at least the IEP protects him from suspension. They come up with creative ways to "punish" him for the infractions, along with counseling and social skills sessions and practice in understanding what it is that he did, but he can't be suspended for three pink slips like someone else would be. That was a good thing in first or second grade (second, I think) when he got six in one year! Last year I think it was only two. Progress.
I wish you the best of luck with this!