TMC-4 — 9 years ago(December 11, 2016 12:13 AM)

All of the scenes involving Hackman were shot by Richard Donner. Hackman out of loyalty to Donner, refused to come back to work under Richard Lester. This is why (if you look and listen closely) there are some shots in which a body and voice double (doing a really rough Gene Hackman imitation) for Lex Luthor are used in some parts to fill in the gaps.
Why isn't Gene Hackman ever called out for being a tad bit unprofessional and self-serving. Don't get me wrong, I don't blame him for wanting to support his friend and I think that most people agree that in hindsight, it was a huge mistake on the Salkinds part to let Richard Donner go.
But it would be quite ignorant to not assume that Christopher Reeve, Margot Kidder and company weren't too please to see Donner let go. But they still had a job to do and had to make the most and the best out of the circumstances. Gene Hackman in a way, inadvertently helped sabotage the movie (or make the situation worse) by not cooperating.