There are certain things about this whole thing that we know were in play and here they are.
1. John Watson could see him the whole time, so he either did something before he got up on the ledge or someone was up there helping him.
2. Molly Hooper helped him, she might deny it, but I know she was in on the plot.
3. A body was found on the pavement, dead, really Sherlock or not, the body was dead.
4. We know he was with Richard Brooks up there, so maybe he was involded before he died or in his death.
5. HE. IS. ALIVE. NOW.
