@ADashOfSalt,
I've been in your shoes. I let my friend vent, just as I would have wanted if I were in his shoes. Nothing replaces the use of a good paid professional when warranted, but nothing replaces a friend who cares either.
I didn't speculate, show my bias, feed his fears, or give him false confidence. My get out of jail free card at the time is the same as yours is now, we just can't know. That's the truth, stick with that and you've done what you can to help him (moral support), and nothing to hurt him, yourself, or anyone else.