Sz 1.5 skier triggered wind slab

Traversing from the top of Ymir on the E side to get to the entrance of the Ymir bench route, we witnessed a skier from another party of 2 trigger a size 1.5 and get carried ~50 m down the slope. The slope was heavily wind loaded and the wind slab was sitting on a very hard crust. They stayed above the surface, were not injured and were able to skin back up to the ridge. Slide happened on a similar aspect/elevation to the one in Kutetl on 03-19.