So my wife and I were flying back to Pullman today out of seattle and we are sitting in 2D and 2E on our little bombardier plane waiting to finish up paperwork. When the gate agent comes onto the place, she says 35 people correct? (It's pullman in the middle of the summer, wasn't surprised at all ) and the flight attendant says no I have 36 people. Then I can't really remember what they said but something like "Oh there was two UPS? instead of one" or something like that and then the other attendant agreed and said goodbye which I thought was weird but didn't think much of it.

Then right as we are about to back out, a women comes rushing up to the flight attendant near the cockpit saying she is on the wrong plane and she is supposed to go to Portland instead of Pullman (both planes were boarding at the same time.) Pullman was at gate 6 while Portland was gate 8. The flight attendant immediately picks up the phone and we stop and go back to the gate (we had moved like 5 feet).

She gets off the plane and the flight attendant looks kinda perplexed as the other attendant comes up and they talk to the pilots and we are delayed 10 minutes to submit new paperwork. A passenger in 1A asked if that had ever happen before and she said "Never! that's the first I have had that happen."

I'm curious who would be at fault in this situation? Flight attendant or passenger? Also, would alaska pay for her flight back out of pullman if they had gone all the way?

I talked to my wife about it but let me know your thoughts!