There seems to be confusion over the avalanche. My understanding is that there are several proposals.
The main theory is some kind of snow collapse/ avalanche/ snow movement / slab slide, happened at the tent.
From there we have several potential outcomes.
1) avalanche/snow slab caused severe injuries at the tent location, hikers cut their way out , the hikers leave to the forest with the injured.
2) small snow collapse /slab slide. Enough to collapse part of the tent and make the hikers cut their way out of the tent .
3) a big avalanche happened and their bodies were scattered to where they were found all the way to the ravine. ( some people have argued this, honest)
If the visibility was poor at the time of installation of the tent AND at the time of said "avalanche/snow slide", then the decision to move to the safety of the forest may have been justified and deemed reasonable given the perceived threat of more unknown snow coming down a slope where you don't know what lies above.
To share my thoughts on this, I think there could have been a small movement of the existing snow where they cut into the slope, combined with fresh snow that had been drifting over a period of hours that evening/night , loading the slope above . Of course, high winds may have added to the situation or added another complication at that moment in time. All that is needed, is the illusion of a serious threat of an avalanche to make the hikers move away , perhaps we do not need an actual avalanche.
Arguments against obvious questions like, why did they not take more clothes? may be down to the simple fact that the more they dug back into the tent , the more fresh loose snow moved towards them. This may explain the difference in foot wear etc. The angle of the ski pole is interesting, when the ski pole is inverted it is used as a peg, the angle of the ski pole at the front of the tent leans towards the tent , this to me, suggests movement of the body of the snow that the ski pole was in. I think the snow would be firm enough for the ski pole not to tilt by wind over three weeks.
It is a hypothetical scenario of course, I was never very good at mathematics.....