He changed his mind. It happens. When he first signed on, probably years ago, he felt one way. Things changed for him. That's not unreasonable. I respect people saying he should give the money back, but I don't really understand why. Sure, that would demonstrate his convictions, but he still did the work. If your company did something you absolutely could not respect over a course of x months, would you return your paycheques in protest? Or would you express your unhappiness, maybe even quit, and go about your life?
I agree that he should never have signed on in the first place - I assume all involved were familiar with the source material. But I don't see why it's so unreasonable that he quietly says he changed his mind, apologizes to his co-workers, and leaves it at that.
Well, he didn't exactly just quietly change his mind and apologize to his co-workers, did he? Rather, he publicly distanced himself from a movie that he made with full knowledge of the subject matter. Plus, being an actor on a movie isn't like working as a clerk at 7-11. If 7-11 starts doing something wrong, it may be hard to discern how much money to return, as it may be hard to know where the problem started. He was contracted to make this movie, so any money he made filming said movie should be returned. Look, I'm not advocating lining the guy up next to the wall and shooting him, but I suppose I am also a little more cynical than you about the motives of a seasoned actor suddenly having issues with the subject matter of a film that he made a year prior with subject matter that wasn't significantly less controversial at the time of filming.