Very interesting write up I must say. It sort of reminded me of the main villain in Deadpool 1 who couldn’t feel pain lol. If I am drawing conclusions from this, I would say Man had CIPA. Funnily, his own was due to some sort of mutation that occured in his life. It wasn’t inherited in an autosomal recessive fashion.
RE: Let's Talk People Who Are Immune To Pain; CIPA