We have included a photo from the group that triggered the avalanche into this report. Big thanks to everyone for passing along their information!
Group involved comments: First ones in that area that day since the storm the day before. Did not see the avalanche in motion, only afterward when looking back. The group believes they would have seen it if it was already there. It was very fresh and the motors would have obscured hearing it. Also, seeing the slope from the trigger area on the ridge isn't possible. Hence, it is most likely they did remote trigger this slab.