nakahara wrote:

....Sherlock´s universe is a peculiar one. In S3 it was established, that you can choose the place near person´s heart and shoot the person into it with such precision, that the person would not die but remains only incapaciated.
...

I agree with the first sentence - very peculiar! However, I've just read a fascinating explantion regarding the rest on http://wellingtongoose.tumblr.com. (Sherlock Medical Essays/On the Shooting) - the bullet wound is apparantly in the safest spot possible if you need to thoroughly incapacitate somebody.

I know Wellington Goose and I enjoyed most of her essays, but there were also some I didn´t agree with - it was this one and the one that claims Lestrade is doing something criminal while asking Sherlock for help (I don´t think so).

Anyway, Schmiezi, a member of this forum posted a long medical meta on the same problem that seemed more probable to me. Click on the "entire work" to read it all:

 http://archiveofourown.org/works/1235479/chapters/2535226

 

Well, if I ever meet (in person) a medically trained person who's closely watched Sherlock I'll ask them. Till then I'll let the question rest...

Having watched this scene just todey, I do have to admit that I was a little shocked, too. Sherlock shows an extremely violent behavior at this very moment - doesn't matter if the cabbie is a mass murderer. What counts is that Sherlock torments a man being almost dead and clearly feeling pain.
Nevertheless, Sherlock was introduced as a "psychopath", a man who is guessed to commit crimes himself in the nearest future, so there's definately a dark, even cruel side to be found in Sherlock. I think's that makes him so fascinating, doesn't it? Partly, at least.