Originally Posted by
Adam Smith
Sometimes when BPs don't scan properly, GAs will look at the BP and mark you boarded by entering your seat number, e.g. 2A.
If they're not paying attention to your BP, that could be part of it. Although how a second person gets on with the same seat number, I'm not quite sure. Perhaps it also flags red and the GA simply attributes it to a system error since the person's BP is indeed valid. But I'm speculating now.
That's what I'd guess.
The SCANNER will not allow you to board the wrong flight.
But the GAs just type in your seat number when they do it manually, and then SHOULD be doing a name check, but apparently not always
One time I attempted to board the wrong flight in SNA because UA had two SNA-SFO flights beside each other, boarding simultaneously, but the scanner errored out. Though it did NOT make the problem obvious. The GA typed in my seat number, then was confused when the name didn't match, then finally realized I was at the wrong gate.