It sounds like the NHS has determined that letting the man die is far cheaper than this surgery and then years of being in the NHS.
308 LBS AT 6’2” is heavy but not to the point of needing surgery. I’m 6’4” and after leaving the Navy I gained a lot. I got up to 302 lbs before going on a diet and getting back to 230 lbs. What he needs to do is stop eating so much.