Even if that doesn't happen, I can see prisons handing out their lawyer's business cards to released inmates. "We are invested in making you a contributing member of society. If you are ever in trouble, let us know - we might be able to help you get back on track."

I don't think that would be a problem. If more people get a good legal defense the system becomes more fair.

But even if you don't like that, you can set up the rule that the prison doesn't get the bonus if the prisoner is charged with a crime. You don't need to tie the bonus to conviction.