I think if you read the story as bad guy turns good guy,...

I think if you read the story as bad guy turns good guy, then clearly it is a cliché. But my experience, when I spent three years working with young people in the townships on issues principally around HIV/AIDS, is that people are usually neither entirely good or bad. They are usually variations of both. Just because someone is a carjacker doesn't mean they are a ruthless cold-blooded murderer.