ChainsawAsh said:
Exactly, that was my thought - they never say that Obi-Wan was the one that caused it. It was in the ROTJ novelization IIRC, but never on screen in the OT.

I think we can safely forget everything that wasn't shown on-screen in ANH, ESB and ROTJ when planning for this (unless we are indeed going to keep some of Zahn's Thrawn Trilogy ideas, like the clones, which I think is a great idea).

Once again it's so entrenched in Star Wars lore that to change it would be like making Chewie an Ewok who fell into a chewing gum machine.