The father said the teacher became upset when his son said he drew himself on the cross.
As reported by the local news station up here.
The child was correct then, as he is the one being 'crucified' now.
I'd take that with a grain of salt. It's not mentioned anywhere other than the Providence Journal article that the boy actually described the picture as himself on the cross. The only related thing I've seen is a mention of the boy having written his name on the picture, and it seems like that fact would be a source of potential confusion for a dimwitted journalist taking sketchy notes over the phone.
According to Saunders, school officials began to quiz the boy about the meaning of the Xs on the eyes and about his understanding of death. At one point the boy said he was actually showing himself on a cross. They called his father.
So the boy only said that it was himself on the cross after they dragged him to the principal's office and worked him over for a little while, at which point they took that one statement and ran with it.
You certainly can't blame a special-needs eight-year-old for getting a a little flustered and misspeaking in a high-stress situation like that. Put yourself in the kid's shoes and imagine you're a suspect in a robbery you didn't commit and the police are peppering you with questions in an interrogation room. If you're making the mistake of answering their questions as best you can, are you going to say exactly what you meant to say in exactly the way you meant to say it the entire time in that situation?
Assuming that that is true I still don't see the problem. A Christian child identifying with Christ's suffering on the cross in a drawing sounds rather normal and healthy to me.