Yes it absolutely could have been stress related, though I didn't make that connection until E Mama (and Cricket2) suggested it. The gym teacher was the first adult he had run into that he didn't get along with. She also had the most complex games I've ever seen children subjected to. Then there were also the two little girls that took every opportunity to tell him what he was doing wrong. Add in the academic mismatch and that does sound like plenty of stressors.
I should clarify that I'm fairly sure that a reputable psychologist using the criterion from the DSM-IV-TR would not have thought my child was autistic at any point. But there are these lists of behaviors out there and the school seemed to be using them instead of the official criterion. The behaviors he had were flapping one hand, complex body movement, failing to respond to his name, not looking anyone in the eye if he could help it, had very selective hearing, looks like he is in his own little world, repeating words and phrases that other say, repeating his own words over and over again, not following the directions, getting stuck on something, prefers to play alone, is very independent for his age, does things early compared to other children, tunes people out, attachment to the schedule and delayed speech.
Some of this list are easily explained. I've known about the speech delay since he was two, but he hit all of the other milestones, most of them early. He also had a complex nonverbal language that he used to compensate for the speech delay. Some of the list of behaviors can be explained by his giftedness. Many can be explained by his belief that he wasn't being heard by the teachers. But I admit, when you look at everything together and compare it to one of those "signs of autism" lists it would be very hard not to think he was autistic.
He still has selective hearing at times, but neither his new teacher nor I will let him get away with it. He will usually tell us "just a minute" now rather then not saying anything. He is also still very independent for his age and does things earlier then most children. However, all of the rest of that list had completely disappeared within a month of starting at the new school.
Master of none, my son also tries out behaviors he observes in other people. I'm just not sure where he was exposed to this sort of behavior. As far as I knew there were no children who exhibited these behaviors in his class. There was a special class for autistic children in the school that had a completely different schedule. I suppose he still could have seen it on the playground somehow. That would help explain it.
Thanks to all of you for your comments and suggestions. I feel a bit less baffled now. If anyone has any other comments or suggestions please add them.
