I don't have time to read all of the relies right now, but I read your post OP. I am in shock. I am so sorry for you and your son that you had to go through that. My heart would be broken to listen to someone speak to my child like that.

I have no great words of advice, except I can say that being a teacher I can see absolutely NO reason to ever, ever speak to a child like that. The is spirit crushing and just plain mean. It is most definitely verbal abuse and again, I'm so sorry.