I am fascinated at the story of the misreported position as the flight left mainland NZ
Personally I wouldn't place great import upon it. Perhaps it was a lovely VFR day and the crew chatted about the beauty of the Queenstown scenery off the starboard beam when they passed, and when it came time for the position report the crew member had a momentary brain fart. I recall being in a TMA and reported being at a different altitude than the one I was at. Stunned silence from ATC, but I quickly amended to the correct number and you could hear the sigh of relief in the controllers voice.
Crews make mistakes on every flight. NASA conducted a study of errors made on airline flight decks and found 899 mistakes on the 60 flights audited.
http://faasafety.gov/files/notices/2...nitoring_2.pdf
Should the pilots have descended into an area unfamiliar to them without first confirming their position on radar.No.
Radar is not permitted to be used as a navigational aid. The reflectivity of radar on ice was a subject of much enquiry during the royal commission and the crew certainly did not have any training in such use as to make a judgement.