[QUOTE=das;7204891]I think they would have called in a backup crew if the crew was going to go illegal. Given SFO is a major UA base, I am not sure this would be a problem in normal circumstances.

There are at least a doen F/As on the aeroplane and four on the flight deck- appreciating SFO is a major 747 hub, would it really be that easy to russle up another crew at midnight who are going to be away from their base for 80 hours
(usually IIRC the crews spend about 55 hours in SYD before returning to the US)