I can't speak for all spectrumers, but I'm prone to the "bystanders effect" like NTs. This video reminds me of a time when I was in a busy supermarket and the fire alarm was going off. It was loud enough to hear, but nobody seemed to be evacuating the store, so it made me assume that maybe we were supposed to ignore the alarm and I carried on shopping like everyone else. Then a voice came through the intercom saying that we have to all evacuate and that the alarm was going (I could tell in her voice that she was telling us all off for ignoring the alarm). So we all had to put down our stuff and troop outside.
There wasn't a fire by the way, and as soon as everyone had come out we were allowed back in again. So it all seemed like a waste of time, as I've never known a fire drill to take place in a supermarket, particularly during the busiest time of the week. I think everyone else were thinking the same and was why they were all ignoring the alarm.