Originally Posted by dtremit

The problem here is that "being at the gate" isn't something that happens in a PNR. That is AA's specific claim here — that OP was required to be at the gate and was not, and that their records prove it.

Given OP's description of being in what they thought was a line to board, it's entirely possible that the agent offloaded them as they were standing ten feet from the desk.

I strongly suspect that if they were offloaded under T-15, AA would have said that directly in their email. That they didn't, and fell back on "not at the gate," makes me suspect they were actually offloaded somewhere between T-30 and T-15.