I place internal consistency over the author's intent. Lucas isn't even the sole author of the Star Wars films -- he collaborated with countless artists, designers, actors, etc. In the case of the RotS "Death Star," ILM for whatever reason modeled and rendered something that is not consistent with the Death Star of episode IV. Lucas can say that it is the Death Star, but that's not what's on the film. (And by film, I mean an some kind of MPEG file or whatever cinematic digital video is rendered as.) If he meant for it to be the Death Star, he should've gone to ILM and told them to get the proportions right. Saying that something on film is something it is not is the worst kind of Special Editionizing -- expecting us to accept a change that he hasn't even bothered to film.

If you'll forgive a reductio ad absurdum, where do you draw the line? What if Lucas says that Luke was actually a female cat-like being with four eyes and a prehensile tail? I mean, if Lucas says Luke is a female cat-like being with four eyes and a prehensile tail he is, simply, a female cat-like being with four eyes and a prehensile tail.