In my opinion, the piece of evidence that is even more compelling than just the location of the nail wounds is the "four-finger" phenomenon on the Shroud. If you look closely at the image, it appears from the configuration of the hands that the person who was wrapped in the Shroud is missing both thumbs.
This in fact is the result of a reflexive action of the human body when one of the three major nerves in the wrist (I believe it is the ulnar nerve) is damaged -- in effect, the thumb is drawn across the palm of the hand in such a way that from the "back" side of the hand it is no longer visible.
Again, this does not "prove" that the Shroud is authentic -- but the notion that someone in the 12th century would have been able to account for this kind of detail borders on preposterous.