Who to blame, who to praise?

I recently saw this brief piece on the web which compared the novel and film versions of Something Wicked This Way Comes. The article mentions in passing that "Disney" made some changes to the story in adapting the novel to film, specifically the invention of some new minor characters.

This first made me smile, because I wondered if the author of the article was aware that the screenplay for the film was written by... Ray Bradbury himself. To "blame" Disney for the alterations seems wrong, if the original author was in control of the adaptation.

But then I had second thoughts.

Although Bradbury receives sole screen credit for the screenplay, it is no secret that the late John Mortimer carried out some uncredited rewrites, under the instruction of the film's director Jack Clayton. Without talking to Bradbury about it, or better still examining the script drafts, it's impossible to be sure how much was Bradbury's and how much was Mortimer's. Or Clayton's. Neither Clayton nor Mortimer are with us any more, so Bradbury is more or less the only one left who we could ask, with the possible exception of the film's producer, Peter Douglas.

But even if we learned whether Bradbury invented a given character himself, that wouldn't necessarily tell us what prompted him to do it. It could be his own free creative choice, or it could be at the suggestion of... "Disney".

I've been having similar thoughts about Bradbury's largely unpublished (and totally unfilmed) screen work in adapting The Martian Chronicles. I am currently studying various materials from the 1950s and 1960s, where Bradbury was attempting to work for a succession of production entities (for want of a better phrase) on bringing MC to the screen. I see an enormous amount of evolution of the script materials, but without access to script notes, correspondence, studio memos and the like, it is impossible to know for sure what motivated many of Bradbury's rewrites.