Just a note here, Joshua lives in Canada. Lawsuits are far less common here and gun violence is quite rare as well. As well, the principal would have some pretty heavy duty explaining if anything else happened to Joshua. Yes, there is accountability in the public school systems in Canada.
I'm just saying that he probably doesn't have to hire a lawyer or prepare for the apocolypse or start packing heat. It was a schoolyard fight and he got a week off. It sounds like he can take care of himself physically. If this escalates into something else a quick call to the school board would probably create ripples the principal doesn't want.