A teacher uses profanity to get through to a hardened streetwise thug who used the 'N' word in his classroom. This boy is a perfect example of a lost young man who doesn't have a male role model at home.
I'm not saying the teacher was right, because respect goes both ways. But we don't know what transpired before another student began recording the verbal exchange.
I did notice that all the boys were wearing shirts and ties, which might explain why they, for the most part, behaved civilized.