"Hip replacement surgery..... with mortality rates extremely low". . that depends on a large number of factors. No.1 is the risk of fatty embolus. when surgery is done the blood pressure is lowered considerably. this allows cholesterol plaques to be come dislodged and so the risk of lumps of cholesterol free in the blood stream. this can lodge in cardiac, cerebral or lung tissue and become a total occlusion within seconds.
he likely wouldn't have felt much discomfort. I just hope his belief in judgement after death happens to him.