Just my thinking, he is in a sorts processing things ... some things we notice most we do not. I would not beat yourself up about the "I coulda done this .. said that" bit, sounds like you caught a glimpse here and there of the old H and that does happen, I would get a taste here and there too but like you said, he has that issue with Mommy Dearest he will most likely need to traverse through and doing that solo is tough ... they do not need counseling as far as they are concerned right?
I think you missed the fact you were there, just being there is often bigger than anything you could say (Can't fix them with a sentence ya know .... can't fix em period) ... in many cases that STFU smoothie works wonders and allows them to really talk to themselves pretending they are talking to us.
