I'm not sure it was a mistake, in the sense of happening by accident. It's probably their sneaky way of getting customers out of the theater.

I used to work for AMC Theatres and Cineplex Odeon; managment's goal was to get as many showings of the popular movies in as possible. If that means your ushers have 5 minutes to clean the theater between showings, too bad. (See how I'm dating myself, this was back in the days when they actually did clean the theaters between showings!)

The common trick in those days was to open the exit doors during the final seconds of the final scene. This caused light to pour into the theater, thus discouraging patrons from staying through the credits.

I won't say I'm proud of having participated in such a scheme, but forgive me, I was only 19 and working my way through college, in no position to stand up to the corporate thugs.

Try calling the theater during a weekday, about a half-hour before the first showing of the day. There should be a manager on the premises at that time, to whom you can explain your situation.