I'm not in the business of picking a particular employee to blame, as there is more than enough humble pie to be served, but a question I would have raised would have been regarding the route from Hallett to McMurdo. Why directly overhead Erebus, and not following the RNC route down the sound?
I understand Air New Zealand chose this particular route (even though the previous flights operated on the other plan) in order to remain clear of military traffic going into McMurdo...