Sector whiteout is well known and well understood.
That may well be true, but that is not what caused the disaster. The whole point of the descent restrictions were to avoid flying into Mt Erebus. They would perhaps appear to be very restrictive, but why they were as they were has been well proven.
There were previous flights that had done VMC descents,but they had all had their position positively identified, and had sighted Mt Erebus prior to going below MSA.
This flight never sighted Mt Erebus, or even positively identified Ross Island before commencing their home made descent procedure.
The only reason Air New Zealand was given the OK to use crews who had no previous experience down at the ice was because if they adhered to the descent procedure as laid down it kept them well clear of Mt Erebus.
That video you keep referring to is good entertainment for people who have no knowledge of things aeronautical, for many it is NZALPA propaganda.