WHBM: Are Boeing sure about the 1989 flight of the QF 747-400 nonstop delivery flight London to Sydney they cite as a previous record ?
It was definitely Sydney. IIRC, they had a mixture of luck en route, but ultimately enough good to outweigh the bad.
Also, IIRC the 340 that went to AKL just refuelled and came straight back. I think it was a stunt pulled for the show that year.