Several courses of incidents?
I’ve been down the rabbit hole again and although I’m sure I didn’t read everything, I’ve been thinking they had prior incidents before settling at that last location. My thinking is an avalanche that hit the comrades who had impact injuries. This would have slowed them down even more, with a worsening weather that made them settle in a vulnerable location. When the snow above the tent slipped, they cut their way out of it and slowly carried each other out. Then, it goes downhill from there.