The revenge of the mexicans

A month ago, four mexican guys rented the appartment downstairs. Today, my mother couldn't stand the noise anymore, and so, at 1am, with the rancheras playing really loud, she decided to go downstairs and ask them to turn off the music. They didn't reply when she rang the bell again and again. Instead, the turned off the music, and then sang a short song themselves, before complete silence took over. They were singing "No pasa nada": "It's alright". My mom thinks they were making fun on her. Anyway. Good thing is they didn't dare to open the door, so they can't know who was ringing their bell (unless they looked through the eye hole, which I doubt considering the amount of alcohol and pot on their blood). I've been told mexicans can be quite violent. In fact, I experienced mexican violence once. Belive me, you'd better take rancheras at 1am.