Ironically, if you have a kid like mine who displays disruptive behavior in class, you'll get a lot of attention. Not the good kind of attention, but at least they take notice. Your son seems to quietly suffer, which seems to be worse in some ways.

Two different challenges, and two different poor responses from respective schools.

But the 504 / IEP question is completely separate from whether he is gifted. I think they are messing with you in that regard.