I had exactly this problem with the driver's door - only for me it locked itself up while the door was open, and I couldn't close the door because the lock was engaged. Somehow I had tapped or hit the small lock catch while I was moving some boxes of gear around, the catch isn't shown, but it's the one that swings into part no 68533 in your diagram. It was forced down farther than it should go and was a complete swine to get back up again. It wouldn't open with any handle, with the key, or by pulling/pushing any of the rods, and nothing was disconnected or broken. I think somehow it just went past its regular position, and there was nothing there in the lock assembly to bring it back.
I spent about 45 minutes prying at it with several small screwdrivers and bits of metal trying to get it to lift again, and eventually got the correct force and angle to do it. I reckon you need to find a way to get to that locking catch...