According to passenger account published on Crikey it seems that the ground handling of pax was poor.
Fair enough, the longer diversion was necessary because of weather at NOU and there was always going to be a delay until the replacement crew arrived (on Virgin!!) but keeping pax on the plane with seatbelts on for 1.5 hours seems harsh. Likewise it appears there was no ground support from QF or JQ groundstaff and all the DFW crew apart from the captain decamped the scene fairly quickly leaving a planeload of tired pax sitting around a transit lounge for $10 with nothing more than a $10 meal voucher.
When NOU became unviable, would it have been viable to continue to AKL? At least there would be significant ground support and replacement flight opportunities there. Maybe there was insufficient fuel and NAN was the only option but QF should have done better for it pax whilst they were stuck there.