I used to work in the operating department of a hospital and have seen some pretty amazing stuff, including a face lift being done, a beating heart in a man's open chest, and loads more stuff, all happening live in front of my eyes. Once, during a hip replacemnet operation, I was splattered with blood as the surgeon chiselled away at the bone. None of this had any effect on me, maybe because it was done in a sterile and controlled environment. The only thing that ever really made me go 'ouch' was the sight of a pipe wider than a mcdonald's straw being inserted into a patients penis to allow blood to drain from his bladder.
Dayv, your story is horrible. I really sympathise with you and your friends (both the one who died and the other one).