Mandy, At some point in time, the olive branch would be a nice gesture. I think I'd wait until just about Christmas and offer the olive branch to him by inviting him over to visit w/his son.
I know you kind of feel sorry for the man and what he's gotten himself into, but you can't help him. Sit back, wait patiently and the answers will come as to when you should offer up an olive branch. I do not feel that right now is the time to do so. It will appear to him as if you are trying to rescue him and/or gloat about his situation. (We know you aren't trying to do that, but you don't know what he's thinking.)
Please think about giving it a bit more time before you shake the olive branch. Okay?
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.