According to the prelim and its' description of the GWI access system, the door could have been opened by the Captain using a 3-digit (+#) "emergency" code. It would seem that it would not be possible to attempt to do so after the initial 1-digit "access request" had been refused
"Any interaction with the keypad is then disabled for 5 minutes".
as this would make the keypad inoperative until approx 9:39.31 (approx 90 seconds before impact).
In the BEA sequence of events, at no time is this "emergency unlock" procedure imlemented, only "buzzing" of the 1-digit access request, use of the cabin intercomm and shouting/knocking on the door (plus some banging that could have been attempts at physical acccess).
Whilst they don't address it specifically, the suggestion of the report is that (in the case of the system in use on GWI) such an attempt could have been blocked by the co-pilot anyway
"If the flight crew toggles the switch during those 15 seconds, the acoustic signal stops and the system reacts according to the command (UNLOCK/LOCK)."
but there is no mention of any such attempt being made - perhaps not surprisingly, given the circumstances and the events of the intervening 5 minutes.
Clearly there are good reasons for the systems that are in place, but, as they highlight, such procedures inevitably introduce an element of compromise and risk.