This happened 2 weeks back, flying ATL to IAD.
A woman about 4 or 5 ahead of me was boarding and the scanner burped when her boarding pass was scanned. The GA tried it again, same result, so he went to his computer and came back to her, handed her the boarding pass and told her to board. Then he grabbed the phone, called someone and said something along the lines of I need Delta techs here, the scanner is screwed up.
So I get to the scanner, scans my BP and it burps, message on the screen says "already on board" - he looks at me and said, "but you already boarded...." (I swear
) to which I reply "actually I'm didn't - i'm right here" - so he does another scurry to the computer, comes back and tells me to go ahead and board but asks me to do him a favor and have one of the FA's call him.....
I get on, tell the first FA I meet to call the GA, then head for my seat. I get to my seat and it has a handbag and a laptop case on it. I clearly see a boarding pass on top of the handbag with the same seat number as mine. The guy in the seat next to my seat tells me that she ran to the rest room.
So we both chat for a minute about how the seats got screwed up and I look at her BP more closely and see DCA on it...
Woman arrives back, I explain the situation, she gets a bit shirty BUT seems she doesn't realize there are two airports in DC (when I ask her which airport in DC she is going to she says "why does it matter") Right around this point the FA comes to get her telling her she is on the wrong flight.
No big deal, but I am really puzzled as to how a) she didn't check the destination or the flight number AND b) how on earth did the GA not spot the problem when she tried to board. Its not like the boarding system didn't tell him.
Just proves that you can have all the systems in place but if humans decide to ignore...