Thanks to the OP for posting. As to how sure he/she is of his/her facts, I would ascertain from the OP's language that he/she is an AA employee, likely a gate agent or someone with a job that requires familiarity with what happens at the gate.

Everyone has had the experience of one agent who is more or less informed than another, and we're always hearing that rule of "if you don't like what one agent tells you, just call back and get a different one." Who knows, maybe another AA employee will chime in with something different to it, something confirming of it, or something additional. In this case, it's easy to see the effort put into explaining it clearly...and, at least it explains a lot of what's going on that the average pax. can't see.