It doesn't matter if it is reluctant or not. He still authorized adaptations of his work. That is the simple facts. The rest is trying to assign his feelings to the situation which was something you said that can't be done yet are now trying to do. The context does matter and the context of the discussion is that he was fine with adaptations because he authorized them to happen.
He could have later regretted that. He could have been fine with it. It doesn't matter because the only thing that matters is he authorized it and he gave away creative control. The act of doing that shows he was fine with it because he didn't cancel the deal.