We had a company executive get-together outside of London a few years ago, so many of us were flying out the same evening on different flights from Boston. I kn

We had a company executive get-together outside of London a few years ago, so many of us were flying out the same evening on different flights from Boston. I knew my ticket was Delta and on an A330, so when we all left the lounge to go to our flights, I glanced outside, saw the Delta A330 and the sign that said London, so I queued up and kept chatting with colleagues. Boarding scan rejected my boarding pass with a red light and loud buzz and I had to walk-of-shame in front of my colleagues down to my actual gate (which was leaving around an hour and a half later, IIRC).