I am curious to know just what they saw on the coast. If you saw the coast clearly for >20km each way would you realise you were not west of Erebus.
People, even those who know a bit about aviation, are being duped by Poor Gnomes, I've spoken with some.
In the mid 60s I flew in a SPANZ DC3 from Dunedin to Auckland via Nelson. It was a spectacular day and the pilot deviated to show us Ruapehu. Don't know what altitude flights typically were, not much above 8000ft I guess. And that's the thing Mahon and Holmes can't see, you have to choose your day. As our pilot did.