deadhead,
Complying with the four points in the briefing paper is a "red herring".
Apart from the initial flights, they were consistently ignored by the airline, although they were left "on the books."
The main point here is that
the pilots were specifically authorised in the company briefing that they could descend in VMC with the approval of McMurdo ATC.
I am waiting for Prospector to claim that this is invalid because it is "I was only following orders" Nuremburg defence.