Originally posted by: Jambe Davdar
Yes Ken Ralston is the guy you are talking about. He mentions that there were last minute changes to the frigate scene at the end of TESB. However, I am unable to confirm as to whether any preview audiences saw the film before these changes were made. Harrison Ford remembers sitting in one preview screening to judge the impact of the 'I know' line, so I guess it's possible. Though this version would undoubtedly only be seen by preview audiences and not the general public.

On the Definitive Collection commentary, Ken Ralston (I think it is) says that there was a finished print shown at the ESB wrap party. He went on vacation, thinking that his work was done, and got a phone call telling him that George wanted to add some FX shots to the finale. Ralston thought it was a joke, as the film was to be released in 3 weeks and they had already viewed a finished print of the film. But, he did have to go back and create some additional shots to extend the ending.

So, it seems impossible that anyone outside those directly involved with the film would have seen the first edit of the finale.