Click to view
The problem with this is that it doesn't make sense. ESPECIALLY from the earlier bit... Joker tried to break Gordon. The fact that he broke Batman, finally, and had Bats kill Joker kind of invalidates the rest of the story.
(Of course the fact that this was made canon pretty much makes it not possible that he killed him.)
I'm also DEEPLY amused by how this has blown up on all the comics sites...