Maybe "Obligated" was too strong a word, probably should have used the word duty?

Duty of care

“Duty of care” is a term used to describe the legal duty owed by one person to another to act in a certain way. As a first aider, you have a duty of care towards your casualties to exercise reasonable care and skill in providing first aid treatment. The duty arises because you have knowledge and skills relevant to a medical emergency situation. If you choose to provide first aid assistance, you have a duty to use your knowledge and skills in a responsible way.

Now it does say choose, so obviously there is still the "opt out" option to walk away? Yes you are correct, once you have started to provide First Aid, then you are "obligated" to remain if safe to do so, until help arrives.

In this scenario, most if not all participants will have at least taken a basic survival course and probably basic First Aid, if not then they don't belong on this Mtn. So as was stated earlier, if the conditions are such then to further risk life was not feasible, according to them then they must think of themselves...however if there was a moment where conditions were such that at least the offer of comfort or possibly have someone stay behind to ensure or try to keep the individual alive until the team can pick him up on the descent, maybe they should have tried?

Which is one reason why I want to go into the Peace Corps and practice outside of the West.
Good Luck....