We all get so used to fictional accounts of medical intervention, where there is most commonly a positive outcome, that we forget just how sad the realities can often be. For example, many fictional storylines have people making quick recoveries from heart attacks when given CPR but the reality is that around 90% of people who are given CPR [outside of a hospital setting] actually die (either immediately or within a few hours or days).
I remember a similarly hard-hitting documentary to the one you mention, Jennyjoan, which was shown on TV many years ago. It featured a cave rescue team who were rescuing an injured pot-holer. The cameras followed the team as they found their way to the victim and then showed him happily chatting to his rescuers and the film crew. Within a short while viewers felt that they really knew the guy, who was definitely 'a bit of a character'.
The rescue seemed to be going well, and there was no great concern over the extent of his injuries, when they reached the last stage of their mission. For that they had to haul the guy (on a stretcher) through a narrow gap leading to the surface, so that, for a short while, nobody could be alongside him to monitor his condition. The cameras were on the surface, waiting to see his smiling, cheerful face but when he was pulled clear of the cave he was found to be dead. I'm sure that it left a lot of viewers in shock.