Another comment on the video. He was asked by the guide to run a diaganol cut, which is a fast angled test run on the top of the slope, and he didn't. It might have sent the slab down without him. At least that is the idea.

It is customary to run some snow tests before skiing the slopes. Ie. dig a pit, look for layers, test the stability on that aspect and angle of slope. Since it was a heli guided situation.. I assume all that was done by an experienced guide?

He was rescued by knowledgable, and capable people with in 4 minutes and 28 seconds, almost unbelievably fast!

People, practice with your safety equipment, please.