If the intervention is unequivocally futile for preserving life it is permitted to not offer care, there are processes in place.
While unlikely, it is possible to survive necrotizing fasciitis and multiple debridements. Although it will come with many months of reconstructions, rehabilitation and pain.
We are legally and ethically obligated to offer heroic life saving measures if there is a chance of surviving. Quality of life is not a factor in our decision making process.
I do not know the exact discussion was had with this patient and their decision maker when incapacitated but it would be extremely unusual for a previously healthy 32 year old to decline heroic interventions, this is also a very rapidly evolving infection where you don’t have much time to think.
With that said I’ve also met 80+ year olds who want major surgeries that will leave them significantly impaired and almost certainly fail despite having time to think. At the end of the day patient autonomy supersedes our thoughts and opinions.