Hempy #123:
“Undoubtedly the phenomenon was not widely known about amongst civilian pilots at the time of the accident. It's probable that no one on the tech crew knew of it's nature. They thought they were in VMC but the conditions meant that the rising ground in front of their mis-identified position was impossible to spot visually against the cloud/horizon.”
The captain knew about the difficulty distinguishing the cloud from the ice. On hearing of the low cloud layer over McMurdo Station, he considered baling out and going elsewhere.