coasterville - What time did this happen?
Generally, if it's before 9:00, the admissions CM at the adventure's club does not swipe tickets unless the guest wants to get his/her wristband or stamp to be ready for the rest of the night. This is because the Adventures Club is FREE until 9:00pm.
From experiance, I know that the CM at Adv. tries his/her best to catch everyone who gets there stamps to make sure the tickets are scanned, and wristbands issued, but if it's a large crowd entering, it's tough.
It's a two step process to enter the clubs. The Club door hosts check ID's, gives a handstamp according to age, and just make sure that you have tickets. Then Admissions crew actually scans the tickets to "use" them, and make sure they are the correct ticket, and issues a wristband if the guest is over 21.