Remotely triggered wind slab

At around 11 AM, my partner and I observed a small, wind slab avalanche crown and debris on a Northeast aspect north of Frazier Basin (Image 1). Prior to seeing that avalanche, we had determined that wind slabs would be our greatest concern of the day, and we had tried to intentionally trigger any wind slabs on small rollovers in controlled terrain. We did not observe any signs of instability prior to seeing this small avalanche. We were stopped on a flat bench on top of a steep rollover talking about how recent we thought the avalanche was when we heard a whumpf, and then a hard wind slab released on the slope below us and ran into the trees below (Image 2). We then decided to enter the avalanche at the bottom of the debris to look at the crown, where we observed that the slab was about 60cm deep at its deepest, and ran around 50 feet wide, wrapping across a small aspect change. We did two ECT tests and observed propagation on the layer during isolation in both tests (SnowPilot profile will be publicly available once SnowPilot is back up). We identified a P hard wind slab overlaying a 3 cm deep layer of 1F hard facets. The layer below the avalanche interface was F hard facets. After this result, we dialed back our ski plans for the day.