I was with a group of friends at a restaurant, we were talking about local bands(we have to organize an event), he asked our opinion on one band and I said that I thought they are boring and he for no logical reason tells me to shut the fuck up if I can't tell him a better band or do it better myself (we had this argument in the past) so in the heat of the moment I called him stupid and childish and started explaining to him that I can give my own opinion even if I can't do it better, after my explanation he got up swearing at me, threatening me and just left. I just stood there confused as why he got that mad, AITA for his leaving?