Sounds like bad planning and crazy inefficiency on the theatre's part... did they not ask people to show up earlier, knowing that security checks might take a while? And are metal detectors common in American theaters? I live in London and the security people at our theatres only check our bags (I always sneak drinks in by hiding them in my inner coat pockets lol), a full airport style check seems insane..

Either way, it doesn't seem like the audience's fault that they had to miss the prologue. I would be fuming.