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In case you wondered why Mark possibly chose this name that does not appear in Canon - I really could not believe it:
And please read the linked BBC article or it does not make sense.
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Interesting thoughts.
The second part of the post about the song is interesting, but I always thought it was more about John looking for Sherlock than relating to Mary, since it's the scene where Sherlock is about to reveal that he's been alive all along.
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There does seem to be a link in that both names link to murder trials, but maybe it's a little bit tenous? The video on the BBC site didn't work for me. Looks like quite a nasty story, although it seems that "Mr Szikora" was a witness who wasn't involved in the murder itself. I'm not sure of the significance of John thinking the "witness" was Sherlock, and being wrong.