I have heard that he was 'bullied' into doing the job and there was a fifth passenger (the child) at the airport when he was only expecting four.
If he was so heavy, how did he manage to fly the hour to Bre, land, fly back via the long way and make it all the way to finals for 19? I understand it would diminish responsiveness slightly, but I think the ATSB were just looking for a more obvious silver bullet. A lack of recency would be a much more logical conclusion IMHO.
When the bright lights of Moree were behind you, things would get awful dark looking to the south. I was talking to a pilot (experienced NVFR) yesterday who had to land on 19 without aircraft landing lights once and explained that he ended up going around and coming in on 01 for the visual horizon that the town offered.