We all were in situations like this. And yes, some have put up with it for a long time, but no, this can't be advocated. This is violence, anger. It isn't assertive, it's just a lashout and I guarantee you his problems just got way worse by doing that. Like 1000 times worse. Interestingly enough, when I was younger I jumped ahead in math during high school, but my school would rotate math and English classes for the same grade, so the only recourse was to put me in a grade 9 remedial course and the teacher gave me a custom curriculum at the normal higher level. This was basically a class of grade 10 and 11 english failures at the grade 9 level. It was an inner city school, and to say the least, the class was filled with interesting characters. Doing work was often really difficult, there were often violent situations and when I first came there as a new to high school kid it was scary. But after like a little while I became friends with a lot of them and got used to it and just learned to assert myself. That's everyone's job not to dissociate. And it got way easier to deal with them once that happened.

TL;DR - the way that kid was acting (if the context were assuming is indeed correct) is not the way to deal with it.