Devils Hill avalanche

Written Report:
Soft slab avalanche, skier triggered on WSW slope at ~6200ft on Devil's Hill.
The start zone had a slope angle that was near 40 degrees in an area of small trees and rocks.
The slab was Fist hardness, soft slab. The bed surface appears to be an ice crust, 1F/P hardness.
When the avalanche was triggered I dug into the bed surface to stop from being carried.
The crown was 18-24" across, slide was 30-40yds+. R2, D1.5. terrain traps but trauma from a heavily treed area was a high likelihood if caught and carried.
No previous signs of instability, all test slopes were stable, the skier was the 4th person on the slope.

Things we did well: Traveled one at a time from safe zone to safe zone, communicated using radios, communicated our comfort with the snow pack, each did individual assessments during the skin up. We avoided wind loaded slopes. The 3 skiers at the bottom began preparing for a search when the first radio call wasn't answered.
What we could have done better: Avoid slopes greater than 30+ degrees given 18+" of new snow in the past 48 hrs. Record the temperature at the start of the ski and be aware of warming that likely contributed to the snow becoming more cohesive and forming a slab.