I dont think a 14 year olds motives are ever clear cut; I do think it was stupendously dumb to make anything that looks this much like a fucking bomb. I also think that it was in exquisitely poor taste to the point where the kid did assume there was a chance he would be dealt the victim card by the time it was over.

Terrorist? No.

Wise ass who saw this coming a mile away? Totally plausible.

Extra credit: imagine how shitty being a middle eastern teen in Texas must be. Who wouldnt be tempted to throw some sand in the gears?