Kindergarten Couloir

Went up to boom lake to ski the kindergarten couloir this morning. Following one party up a skin track, as we were coming up the cone towards the couloir one member from the other party stepped under the couloir and did what appeared to be hand shear tests and then proceeded to transition and descend the slope below the couloir rather than ascend. We were close enough to see what they were doing but no communication was made prior to them descending as per what made their decision although I would be curious. Approx 5 minutes after they descended a size 1.5/2 loose dry avalanche came down the couloir running down approx 80% of the fan below. It was silent and gaining mass as it came down the couloir and was enough mass to bury although loose dry. This pulled down most of the snowpack resulting in just some debris being left in the couloir. Rock and ground is exposed in some sections with a mix of debris in others. There were large sluffs coming out of the slot to the lookers right of the couloir running down about 30% of those fans. Light was too flat for photos to turn out