So - imagine this. You're a pilot and you decide to step out of the cockpit to visit the bathroom. When you get back, you find that you can't open the door to the cockpit. You're locked out. This actually happened. The flight attendant and First Officer were still in the cockpit, but couldn't get the door open with 20 minutes left in the flight. They finally got it open and the pilot got to land the aircraft.
Yeah. I know what really happened. The First Officer said to the attendant, "I'll give you $100 if when the pilot tries to get back in, you hold the door closed and we pretend it's stuck."