I'm so sorry your son went thru that. When DS was placed in K when he was newly 4 the teacher didn't put his photo on his cubby like the other kids, she didn't let him have a journal or a pencil box and she let the other kids tell him he wasn't allowed to use the computer because he "wasn't really in Kindergarten." Then she gave him a zero on his report card for "use of technology". <eyeroll>

It sounds to me like those teachers just wanted to prove to you that your son didn't belong there by making things difficult for him. It would have taken a little effort on their parts to include him but they just couldn't be bothered...

I'm ticked off all over again just thinking about it! And I'm mad on behalf of your son, too.