Around 3pm, while traversing west across the southeast face of False Flagstaff (above Flagstaff shoulder and about 40' down from the summit), my partner triggered this D1.5 (enough force to carry but not bury, except in a terrain trap) wet loose slide. We made observations (hand shears, ski pen, watching for rollerballs & other WL activity) on the way up, but noticed no signs of instability. The difference was that this slope was much steeper than the slopes we'd made our observations on and consequently had received much more solar energy. Fortunately, we were employing safe travel habits, and this slide was triggered during a ski cut, so my partner was not in danger from the loose snow breaking at his feet. We proceeded to ski directly down the shoulder to stick to lower-angle terrain. We noted no wet loose reactivity on these lower-angled slopes and on the southeasterly aspects of the shoulder.