GAs are charged with getting the flight off the gate in time, baring items outside of their control (maintenance, loading baggage, crew available for pushback, etc.) IIRC they must document why a flight that should have left on time did not (something within their control). So they constantly have to make a judgment call. How would the GA know where the OP and his traveling companions stood in the customs clearing process. Now, granted it appears as though the GA could have been more professional. However, AA did provide for overnight accommodations, something which AA did not have to do.