Perhaps the union became involved because they pushed for the flights to be shared amongst their senior captains. This was against all the accumulated wisdom of all the operators who have been operating down to the ice for many years. The experience requirements for operating in Antarctic regions was completely disregarded.
This from 'A History of Civil Aviation in New Zealand" by Maurice McGreal.
The reality of the judgement of Erebus must rest in the knowledge that flying is a dangerous business and nothing has replaced the crucial role of the pilot in the whole scheme of things, for when we think about it, the prime role of a pilot is not to have an accident. To help him or her achieve this result, no let or hinder should be acceptable and this applies to those on the ground who prepare the data for use in flight
This from "The Erebus Enquiry, a Tragic Miscarriage of Justice," compiled by C.H.N. L'eSTRANGE.
"his final sentence has these damning words'..once airborne, the captain is finally and totally responsible for the safe flight operation"