I think the time to call for help is when you feel youneed assistance. The situations you describe as not as clear cut and definite ass say, a broken leg, but I could easily imagine them being quite valid. It is much better to help someone off the mountain before the storm (and easier!) than removing their frozen body after wards. There are blisters and there are blisters. I have seen cases where it would have been very difficult, if not dangerous, to hike out (blood spilling out of the boot makes for treacherous footing).

It is not a good practice for SAR folks to second guess the decision of a victim to pull the trigger and ask for help. People and their capability vary enormously and situations can change suddenly.

An extreme situation - in two operations, the victims wound up arrested and in jail because of crimes they committed just prior to getting in trouble. Rescue first, analyze later.