Mr Eden said the snow around the crater area was mostly hard at this time of year and it appeared the climbers might not have been carrying snow-shovels.
"It shows that if it was only waist deep, it was difficult to dig. It would have been only ice-axes I imagine."
"I wouldn't think that they had sleeping bags. They wouldn't have planned to spend the night out given the [poor] weather forecast."
He said that arriving at the top of the East Ridge climb in the crater area at 7pm was "just ridiculous". It suggested something had gone wrong on the climb to slow them down - gear failure, or perhaps an injury.
The Taranaki East Ridge climb in spring is graded at 2 on the Aoraki-Mt Cook system; the most commonly-used climb on Aoraki-Mt Cook, the Linda Glacier route, is graded 3.
Mr Eden said the East Ridge ascent typically took up to 4 hours to complete in winter and spring without using a rope. Using a rope, and snow-stakes or ice-screws, more than doubled that time.
He said a rope wasn't usually used on the climb by fit and competent climbers.