A bit of warning: there are spoilers for The Reichenbach Fall contained herein.
There is a line of ‘reasoning’ coursing through the Sherlock fan community that the person responsible for confirming the death of Sherlock Holmes is also the sniper assigned to put out the light of John Watson’s life were the former to ignore his duty of committing suicide and completing Moriarty’s grand scheme of defamation. The problem with this is that, like many fan theories, when you put it to the test of logic it fails, rather miserably. It is my sincere belief that there were other people watching Sherlock, but John’s sniper was not one of them.
During a conversation with another user on Reddit on this very subject, I was charged with watching the scene again, because, from their perspective, doing so would prove that I was wrong. I did so, watching very carefully and taking notes, and now I will bear the fruits of my labour here. Because I care.
Jim Moriarty: Three bullets. Three gunmen. Three victims. There’s no stopping them now… Unless my people see you jump.
Moriarty was a genius. He was a mad, brilliant, meticulous genius, a spider, as Sherlock referred to him earlier in the episode, who sits at the centre of his web and knows where each and every one of his threads leads, how they interact, and whether one of them reacts to even the smallest of movement. He was especially careful, it seemed, when dealing with Sherlock Holmes. Sherlock didn’t sneeze without Moriarty knowing about it; evidence of this is strewn about in both The Great Game and Reichenbach, and probably other episodes as well.
I point this out because it shows that Moriarty isn’t going to say something just for the sake of fancy. This means, then, that the statement I quoted above implies that, despite the fact that the spider is there on the roof with his prey, he’s still already got people set up to observe Sherlock’s suicide. He isn’t going to call off the assassins, even if he witnesses the death himself because he’s got others to do his dirty work for him.
This is the first strike against the theory that the sniper is the one responsible for verifying Sherlock’s death. The first glimpse we get of him occurs during Sherlock’s bout of panic on the hospital roof, after Moriarty has relieved his cranium of his brains. The issue here is that the time at which Sherlock was to jump, if he did at all, was a variable in the plan. In order for this variable to be accounted for, Sherlock would have had to have been observed right from the beginning, as in, as soon as he stepped through the roof access door. John’s sniper wasn’t present at his vantage point for a good five minutes or so after that.
The second strike against this theory is that the sniper had been hired to kill John in the event that Sherlock refused to jump. This meant that he would have had to keep his crosshairs on John the entire time he was trained on him for maximum opportunity of a good killshot. The purpose of a scope on a rifle is to pull a target into focus, and it doesn’t leave a lot of room to view the surrounding area. Basically, the sniper couldn’t have watched Sherlock to verify that he’d jumped because the scope limited his vision. He literally would have been unable to see the suicide. Had he taken his eyes off John in order to make visual confirmation of whether or not Sherlock had jumped, he would have run the risk of losing his target completely and failing his mission.
The third strike falls against what is perhaps the most ridiculous aspect found in a good majority of the sniper theories, which is the speculation that the sniper was, in fact, the one to verify Sherlock’s death, and that he did so by observing John’s reaction to the fall. The fact that this theory remains in effect at all is baffling… I touched on it very briefly in my earlier Sherlock article, and the point still stands: this theory assumes that Jim Moriarty is a moron. Considering how meticulous and careful he is with Sherlock, and that Sherlock is the only person he can consider a rival, Moriarty isn’t going to leave the verification of his death up to the distraught reaction of John. He would want to be damned certain that Sherlock was dead, so he would have people watching to properly ascertain that fact, not rely on a basically second hand account of the incident.
I’ve no doubt Moriarty’s people were watching Sherlock, though who knows from where. They could have been in other buildings, or perhaps the driver of that oh-so-important laundry lorry, or even one or more of the people on the ground. I don’t know, really, and I again don’t really care. I will wait, and I will see. However, I cannot comply with the theory that one of these people was John’s sniper, as it just doesn’t make any bloody sense logically.