Interesting . . . .
Getting script revisions is not all that common. Fortunately, somebody at the studio has to read and approve the finished ms. and this is often where any changes from the original script get caught:
"Oh, we cut the windmill scene. And that kindly old doctor? He's now a sexy babe."
This is generally your last chance to fix things, although there are always
going to be minor discrepancies between the movie and the novelization, simply because the writer has never seen the movie!