If it was flexible, it could move in a breeze. The news reported they found his pants. It seems he got hypothermia-caused dementia.
I was hiking once high up in the White Mountains and a freezing cloud came in. It had been sunny and warm where I started but we had gone too far and I wasn't dressed warmly enough. After my body temperature had dropped to the point where I could barely move, I became completely irrational and began to fight the guy who was with me when he insisted that I stay on the trail. He was bigger and more warmly dressed than I was and he was simply cold but had not gone all the way to hypothermia. He virtually dragged me down the mountain and I was apparently fighting all the way.
I think Kim had also probably not eaten for a few days, which makes it even worse. Poor man, but he died heroically while trying to save his family. Prayers for all of them.