The problem I see here is the fact that 2 consecutive LAX-SYD flights went mx. I know that there are no (maybe 1) 747s laying around and waiting to be put in service in case of mx but they had 24 hours to find the airworthy replacement and they failed. It didn't have to come to the point where everyone is on board for them to figure out something is wrong on the second day. They could have proactively transferred at least this one pax to SFO-SYD or any other carrier (SQ, NZ, Delta, anyone) if they cared at least a bit for his situation.