^ I partly agree. Sherlock had obviously had time to prepare this whole thing and had predicted it somewhat as evidenced by his earlier conversation with Molly.
But he has John stand in a spot that specifically prevented him from seeing the impact spot. I don't think Sherlock really fell. I think everybody at the scene was an actor, hired to quickly arrange the scene, add the fake blood and to keep John from getting close enough to inspect the body for long enough to verify that it wasn't really Sherlock. Also they are careful not to show a direct line of sight from Holmes position (as he jumps) to Watson on the street, only, apparently, the other way round.