From my limited understanding, causing death by a dangerous act has no equivalent in NZ, therefore cannot be extradited. NT gov is apparently changing the legislation abolishing that charge and replacing it with/under a manslaughter charge. Hence the reason the initial charge has been dropped and you can probably bet a new charge of manslughter will be on the cards when the legislation passes.
RFDS is a free service to all that it transfers, primarily funded by the NT Government when operating in the NT, so having insurance is irrelevant. They also are primarily a medical transport service, so they most likely will not report anything the police anyway.
Accidents do happen, whilst tragic as it was. Allegedly it was common practice to use that type of "lantern" at this particular station, and the pilot was only doing as he had been shown.
Knowing the NT justice system as limited as I do, I would much rather be charged for manslaughter here than anywhere else, may get 100 hrs community service and a slap on the wrist.