Although I do wonder about the compass thing. It sounds like they were not too far and I wonder if they could have made their way to Muir, even in whiteout conditions with a compass.
Of course w/70 mph winds and whiteout...
It sounds like one of those mini pads could have made a difference too and they are not heavy at all.
As we've seen before, it seems like the difference between survival and not can often be very little.
-john