Looks like the weather turned on them.
it was snowing at 11,800'. they chose to continue on to the summit of 14,505.
video here:
climb couldn't see the trail for the snow and whiteout.
the summit is rocks with a small path winding through them. with snow, that winding path would be obliterated in a short amount of time.
they were dressed for an autumn day hike. they found winter.