Even if he was where he thought he was, he would still have flown within 3 nautical miles of Ross Island, whose summit is about 13000 feet, at a height of 10000 feet, at a speed of 260 knots. And if he was so certain of his position, with the high ground of Ross Island to his left, why didn’t he turn right when attempting to climb out? His first officer had just told him that it was clear to the right, yet the captain turned left, towards where he is supposed have thought the high ground was. The answer, I think, is that the penny finally dropped and he recalled what had been said to him at the briefing, which was that the final waypoint was at the NDB at McMurdo Station. If so, the nav track would go right over the summit of Erebus, which meant that Mount Bird would be to the right, so the only way out was left.