Biting:

Clearly natural instinct to clamp down with jaws if foreign object forciably enters mouth (potential crossface or even headlock)

I doubt it was intential... if it was intential kid would probably have history of this behavior.

AD to eliminate kid from Regionals?? I would go above AD. School board or State. Does this AD kick a kid off the football team if he gets an unneccessary roughness call? Does he sit a basketball coach without pay when he gets a technical? Same with throwing a baseball coach out of a game, arguing a call?

It is wrong to be a bad sport. But consequences need to be based a clear hard evedience... like teethmarks on the back..