4 Now Abimelek had not gone near her, so he said, “Lord, will you destroy an innocent nation? 5 Did he not say to me, ‘She is my sister,’ and didn’t she also say, ‘He is my brother’? I have done this with a clear conscience and clean hands.”
6 Then God said to him in the dream, “Yes, I know you did this with a clear conscience, and so I have kept you from sinning against me. That is why I did not let you touch her."
Poor Abimelek probably thought he freely refrained from touching her, thought that he could have touched her but didn't. Abimelek might have even thought his future regarding Sarah was a garden of forking paths. His common sense belief didn't match reality, though; in fact, he ceased to be a moral agent at this moment. At this moment God ontologically changed Abimelek's flesh into felt, securing strings on him, and controlling him via "meticulous, anal retentive providence." At this moment, Abimelek became a puppet.
What's more unfortunate for some theologies is that it appears God can keep people from sinning without creating a "massively different world" from what we see now. Either he violated Abimelek's libertarian free will doing what he did, or he did not. If he did, he was able to do so conspicuously (contrary to the claim of some Arminian apologists). If he did not, then why doesn't the Arminian God do this more often? He can keep Abimelek from sinning against God and from touching Sarah while not keeping David Westerfield from sinning against God and from touching Danielle van Dam? Did God love Sarah more than Danielle? Did he like Abimelek more than Westerfield? What love is this!?