The wind-scoured tracks and axe holes suggest the three were going up together. I wonder where the anchor was relative to the snow caves. It seems to suggest that two tried to rap down from the upper cave. Its a little odd that they would have left the rope as a rap anchor, the way it is tied it couldn't be retrieved and it would have been useful for the terrain below. Maybe they didn't have any long slings, but then why didn't they cut a piece of the rope off? If they went down the Elliot, the best hope is that they are in a schrund or crevasse lower down and alive but unable to climb out...hope for the best.