Because the system is so aggressively safety oriented, if the alarm triggers, it will not stop until the problem is corrected.
Which means, if the alarm goes off because someone pulled it, it won't shut up until the pull station has been fixed. (Which is hard because there is a special key that will reset these things. You can't just pop them back into place.)
Even if you hit "Reset." It'll just keep triggering. And even if you hit "Silence," it will still notify the monitoring company.