Benedict Cumberbatch and Martin Freeman couldn't attend the Sherlock panel at Comic-Con, but they were able to send a video message in their place. Freeman just gives a pleasant hello, but Cumberbatch decides to reveal the secret of how Sherlock survived his seemingly deadly fall in the season 2 finale... kind of.
Hilariously enough, I'm pretty sure Cumberbatch is genuinely explaining what happened underneath the "signal lost," albeit peppered with some extreme silliness. I remember Sherlock asking the coroner for a favor, which meant he could get his hands on a corpse, hence the monkey switch; there was a truck of some kind of soft material hanging around on the street that he could jump into from off the building; and I think he had more than a few minions on the ground that could place the corpse on the ground for him while he hid himself — remember how someone prevented Watson from getting too close a look at the body?
That said, I want Benedict Cumberbatch to explain everything to me with small plush monkeys from now on.