I saw that story yesterday and I'd really like to know how he even got on the international flight in the first place before blaming United or the passenger. If he took a wrong turn boarding from 75A and ended up somehow going down the passage to 77 ... well, how is that allowed by the airport? There's not a physical barrier between domestic and international departure gates? Yes, United's checks should have caught the fact he didn't belong on the flight before they took off but he shouldn't have had access to the flight gate and shouldn't have boarded the wrong airplane in the first place.