Sad to hear that, for a few years ago I lost a friend for the same reason doing the same job in the Spanish side of the Pyrinees working for the Cataluņa Fire Dept. Mountain Rescue Service. They also had stones falling into the main rotor of a BO 105 after dropping some of the rescuers that saw the hole thing from near by.
I strongly support the developing of a Helicopter Rescue association so we could share experiences and learn from each other. I think we deserve it and need it.
Buen vuelo and condolences to the families