I once waited 9 minutes for a guy who was with his family of wife and 2 children on their summer holiday to Alicante who had lost his passport between check-in and the gate. He went back to security to get it, had to convince them he was the owner, (4 mins) then ran back to the gate and got on. Arrived in ALC 15 mins ahead of schedule.
Result, letter waiting for me when I landed back in UK that afternoon and a subsequent warning on my file for 12 months.
Never did it again........more than my job was worth.
Most of you will guess who I was working for at the time.