Heh, pet umbrella indeed.
Caught more thing on my million and third viewing of RF - and went to the screen shots to confirm this because I found it odd and in line with some of the theories about body doubles or there being a group of people to do some kind of trampoline catch and then let him fall on the ground.
While speaking to Moriarty, he looks down to observe, and Moriarty makes a remark about an audience: http://sc.aithine.org/sherlock/203/23/sherlock-203-22171.jpg
But as we see him fall - after the cut to John, there is no one around his landing place to be seen: http://sc.aithine.org/sherlock/203/25/sherlock-203-24406.jpg
The landscape also looks very different and there are no buses.
Anyway, just thought I would pass along my Sunday musing. Also, this screenshot site is so awesome (though might be cheating ;-) )