The seatbelt sign was off from the time the aircraft arrived at the remote bay until just before it was towed over to the terminal. Certainly passengers in the front part of the aircraft were moving about freely. I'm not sure why this comment was made.
For a short period after the aircraft arrived, the passengers were asked not to use the lavs, as the 'honey tanker' was sucking out the waste and the water tanker was refilling the potable tank in preparation for a possible departure. The water does not flow during this time.
Qantas' handling agent in Nadi is a local company called ATS. They did a sterling job of cleaning the aircraft, servicing it and whistling up nearly 300 meals at short notice for the NAN-BNE flight. [How do they do that?]. Their uniformed staff did a pretty good job under the circumstances. Unfortunately, they could not give any answers to the most frequent question, 'so, what happens to my connection to XXX' as those decisions are not made by 'head office' until the aircraft's arrival time at Australian ports is accurately known.