These things are mainly the responsibility of the concert crew/stage manager, though. Yes, it's shitty of Mayhem to play longer but ultimately the blame lies on the stage manager. If you are over your allotted time, you get cut off, it's so simple. I never understand why people let any band overplay by more than 1-2 minutes when there is a curfew ...
well put yourselves in the shoes of the stage manager. Mayhem is playing, obviously someone in the audience is liking it, and you suddenly cut them off, they say "these guys just cut us off" or simply look angry, and now you have instant chaos. It's hard to grab a mic and tell everyone "hey guys we had to cut them off cause they were being meanies to Asphyx and we have to finish early". I mean sure, many people would be glad mayhem ended cause many would be waiting for Asphyx, but a lot of people would be angry to see Mayhem cut off in the middle of a song.
A couple months ago I saw Entombed at a local place that is normally a discotheque (you know, those places with technomusic and people go to dance and shit) but is also used for metal shows sometimes, and the thing with the show is that it has to end at a certain hour because after that hour is when the welldressed and perfumed people go to dance techno music (I think the limit imposed by the venue was 2 or 2:30). But Entombed had a veery long set and the show started with a bit of delay, so I could see how the organizers from the backstage were making signs of "two more songs" when there were like 9 songs left or so (I could see al this cause I was in front row, I could see the backstage and I had the guitarist's setlist right in front of me), and they kept on playing with a smiling face. Many times the guy went on stage, said stuff in their ear and the band was like "yeah cool no prob" and kept on playing, song after song without stopping, and I could see the face of desperation in the organizer, but they just couldn't cut them down, because the audience was nuts. If they had cut the band out, people would've gone crazy, wouldn't have left the venue to let the techo music begin, probably would've stolen equipment (hey, that does happen in Latin America hahaha), etc.
So I don't think it's the stage manager's fault, I think it's the band who are being assholes
