This was a planned trip, organized in advance by three leaders.
True, it was.
IMO, this raises even more questions/concerns. How much trust/faith should a person put in the folks organizing such trips? Should we not take the same precautions/preps that we would take if we were going alone? I don't know. But I have found over the years that Mr. Murphy is always watching me and has a sense of humor. That is, when I depend on others, it turns out I shouldn't have.
What might be interesting to discuss, if you were the leaders of this group, what instructions should you have given them about what to bring with them on the trip? For example, I think I would have told them at least something to the extent that "weather in the mountains can change quickly-- please bring a warm sweater, and a light rain jacket, preferably with a hood-- if you don't have this bring a jacket and a dollar store poncho and warm hat.-- also, try to wear warm/water proof shoes/boots, or bring a change of shoes and socks."
It seems, at least for this group, hypothermia was the biggest risk. My old NCO training convinced me it was my duty as a buck sergeant to try to watch out for the guys under me. While I think there was a lot of failure to go around, the group leaders should know better.
Even with that said, my belief is that we are all responsible for ourselves -- if we are in trouble, we can't help those who are.