I really don't like it when people do that, but like you said, you seem to be forced out the doors by the stampede of guests. I think the doors should be locked until the end of the preshow. 
Who would do that... :roll:
I have to say i went on RnRC 4 times when i went with my mates and since my friend lent against the door and it opened weve never stayed and watched the pre show :lol: