The guy spent about 10-15 in prison and even though he managed to prove his innocence after the woman admitted it wasn't him, he didn't forgive the woman and money wasn't good enough for him. He was very upset that his life was ruined. Basically he felt what happened to him was unforgivable.
If you were that guy would that still be unforgivable? Yes, the woman did got raped but she sent the wrong guy to prison.