Ehm... are you trying to tell me they weren't able to get Mark Hamill to record a scream for ESB back when it was made?! Or that Greedo shooting first was impossible to make back when they did ANH? If you are, I'm not agreeing on that one for sure.
Imho, that was Lucas changing his mind and trying to cram those changes in there by all means necessary, regardless of how fake it would seem. That gives me the impression that he just wanted to get back at the people who forced any sort of compromise upon him back then.