Originally Posted by iapetus

Come to think of it, I actually have gotten bitten by this. I got to my gate for a flight a bit late at ORD last year, as my connection was tight and we were a bit late arriving. Though I was in Y, I had G1 access and waited patiently in line behind the other G1 pax. However, they were boarding Gs 3, 4 and, finally, 5. Other G1 and G2 pax who showed up after me were also confused. The GA explained that there was a problem in first class; so other groups were boarding first. I was getting anxious because I was concerned that I wouldn't be able to find overhead bin space in Y. So, when G1 was finally invited to board, I pointed out to the GA that not all G1 pax are in first. He dismissively replied that he had said earlier that he was only asking G1 F pax to wait (I did not hear that part; I presume that he had made this detail clear only once).

Annoyed as I was, I did find overhead bin space. No harm, no foul after all, I guess.