Originally Posted by
Jazzed69
If you check in a bag but don't show up at the gate, we will 'sequence' your bag. That means, we will track down (approximately) where it is in the plane and pull it off. 9 times out of 10 if you show up DURING the sequencing process, the gate agent will allow you to board to minimize the delay, but if you show up after the bag as been pulled, you aren't getting on that plane. Please do yourself and your agents a favour and be on board at least 10 minutes prior to departure!
But that's just it! How do you know if a passenger is on the plane or not? There's no scanning of the BP, you don't collect any parts of the BP. In this case the gate agent just looked that the names on the BP and ID matched.