Okay, major Sherlock spoilers ahoy…
I think the idea
here is great (scroll about halfway down the page to get to it). In the episode the thread about the little girl screaming when she saw Sherlock wasn’t tied up, and I forgot about it when I was watching the first time because I just assumed that Moriarty had shown her pictures of Sherlock whilst torturing her or something to that effect. Now that it’s been bought to my attention I think that the impersonator theory is great, and Molly certainly would have had access to his corpse.
The bit where this theory falls down is the part about the multiple rooftops. There is one shot that clearly shows Sherlock is standing on the building that John is looking at - the view of the camera is from the top of that building, next to Sherlock, and it pans from John standing on the street to Sherlock’s face. So he is definitely there.
Now I’ll address the points I mentioned earlier.
- Sherlock NEEDS John to be standing in a very particular location. When John first arrives Sherlock says to him “Turn around and walk back to where you came from… JUST DO AS I ASK… please… stop there.” The second time is just before he jumps, and John starts to walk back towards the hospital. Sherlock says “No, stay exactly where you are. Don’t move. Keep your eyes fixed on me! Please will you do this for me.” He seems especially panicked on these two occasions, like he really doesn’t want John to move from the spot.
- The place where Sherlock is making John stand ensures that the one story high Red Brick Building (as seen below) is placed between them at all times. I first noticed the Red Brick Building from this shot when John first arrives on the scene and is running towards the hospital:
- When he returns to the location where Sherlock tells him to stop, he is standing with the Red Brick Building between them - you can see the roof:
- Here is another shot, showing John’s perspective of the Red Brick Building:
- Now I’ll move on to our perspective of the fall, before getting back to John. This is the first shot we see of Sherlock falling (and I do believe it is him jumping from the building), which also happens to be John’s perspective.
- The angle then switches to a shot underneath Sherlock, from the pavement below.
- It seems to me that this camera angle change is to prevent us seeing too much from John’s perspective (more on that in a second). We then (apparently) see Sherlock’s body hit the pavement with a thud.
- Why take us away from John’s perspective? Because John doesn’t actually see Sherlock hit the pavement - his view is obscured by the Red Brick Building, but this isn’t made clear to the audience. That his view is blocked is subtly made apparent as he walks towards the scene, just before he is hit by the cyclist.
- There is one more thing in the above picture which may seem inconsequential, but I think is actually quite important - the truck which is also in front of (what we are led to believe is) Sherlock’s body. This truck is seen pulling away in the very top of the next shot.
- So, my theory is that Sherlock himself did indeed jump off the building, but he landed in the back of the truck (presumably onto some sort of soft material which was placed in the back to cushion his fall). At the moment he lands in the back, some accomplices (I like the ‘Homeless Network’ theory, along with Molly) throw the corpse of the Sherlock impersonator from the back of the truck, onto the ground, in order to made the ‘thud’ that John would be expecting. The camera shots in the falling sequence don’t discredit this theory - we see Sherlock, falling and flailing, in the ‘pavement viewpoint’ shot, but when it changes to the ‘hitting the ground’ shot we are actually seeing the impersonator hitting the ground, after being thrown from the back of the truck. All the while John’s view is obscured by the Red Brick Building. “Keep your eyes fixed on me” - Sherlock really does not want John looking at what is going on around him…
- Incidentally, I think that John being hit by the cyclist is purposeful, not to disorient him, but to buy a little more time to ensure the corpse is ‘bleeding’ and for Sherlock to make his getaway in the truck.
I think having a passing interest in magic tricks and how they are performed helped me with this - a lot of that is noticing the things that appear to be inconsequential, but are in fact the key to the trick. In this case it is the Red Brick Building (which I actually noticed the first time I watched the episode, but didn’t put everything together until tonight), and the truck.
TA DAA!!
ETA: I do think that jumping from the top of a building of that height in to the back of a truck is highly unlikely in real life (though I think it would probably result in major injury rather than death), but it is the type of thing that an audience is usually entirely happy to suspend their disbelief for in fiction. Maybe there was a slightly different landing spot, I don’t know, but I think it’s only a very minor problem with the theory.