Now, for the 'rush' times they have a second person there who will check the passes and they leave the barrier up. When I arrive its usually before this happens (the barriers are usually on 'automatic' or more often just left up). The car ahead of me went through the barrier and the 'guard' waved me through - except the other guard hadn't hit the 'leave barrier up' switch so it almost hit my car (proves my brakes worked).
No harm done and we all had a good laugh (couple of apologetic looks from the guards) - its all good fun. I know a lot of the guards (as well as porters, cleaners etc) and enjoy some good banter with them.
Good smile for first thing and also made sure I was awake (I think they did that on purpose ;-) ).