Absolutely correct about they needed protection immediately, Holmgren says “ they covered the tent with snow to secure it from blowing away, The photo shows chunks of snow on the tent, even Josh Gates pointed this out. For sure it would not be a conventional snow wall...Observe the 2 photos of them digging out the tent, the exterior snow pack , where the skis and backpacks are located are higher than the interior of the tent floor causing a natural wall.. What’s never been reported, to my knowledge, are the skis that have been stuck into the ground, may have inadvertently fractured a snow slab the tourists never realized was there that, eventually crashed down on top of them.. My eye is telling me that the photos of them digging out the area to set up Their tent, is not, the same area where they found the tent , Unless the tourist happened upon a false wall of snow that eventually slipped..then the gale force wind blew Most of that wall away....Even though this theory could be ridiculous, but I agree with you wholeheartedly on your theories.