Suspected remote trigger - E aspect dropping into Cool Lars Couloir

First party dropped into the cool lars couloir while we were transitioning. Ate lunch and had a small break during transitioning. There was probably 15 minutes between us from when we last saw them to us dropping in. No other party ahead of us heading toward the couloir. Upper tracks in photo (near crown) are theirs, ours were just below it. Suspected remote trigger as there are no tracks near or around it, save for the downslope tracks shown in photo. Slope was concave and a small feature. Did not investigate avalanche bed for type of WL underneath.