He had already had his time. Obviously, "hero" is hyperbole. Alliteration.. "hero or heel?"Yeah. I'm with the not cool crowd on this one. How would you feel if you were in his position? I know I'd be pretty mad.
Heck, I'm not the best singer or bassist in the world, but when I am on stage singing or playing that's my time. Not yours. Just because something annoys you doesn't give your the right to act like a jerk to change it. You should have just asked the band if you could sing with them on another song. You ruined and embarrassed that other dude. On no level does a "hero" do that to another person. Hero's help people.
More than a few people thanked me later. But they were tipsy, too. Good times.