I direct this scenario to compressor stall and maybe megan, as you two appear to be the only ones in recent posts to have a qualified handle on the subject of whiteout. Apologies to others who have spoken about it.
Would it be reasonable to assume if they were flying over McMurdo Sound they would not have encountered this visibility problem of whiteout? So if they thought they were where they should have been, what were they expecting to see and what did they actually see? Visibility seemed OK from the CVR, forecast weather and passenger photos so maybe it was the route change that fooled them. They were not where they expected to be and because of whiteout, they did not see what they expected to see. Is that fair or not?
You might say one may really have to consult with the crew to find out what happened. I know that is not possible so I'm not surprised this accident is so fiercely argued about.