If I were a coach and had a player who did what Johns did, I would'nt have shafted him for having a problem. I would have tried to have southg help for him, as I'm sure many did, but ultimately it is up to him to help himself.
What was his other choice, sacking him and exposing him and destroying his career prematurely?
There are probably dozens of players in the NRL who coaches try to keep a lid on their problems one way or another.
For a parallel example, look at the AFL and West Coast - nearly half the team are on the gear and they only seem to care when it becomes a case they can no longer manage in Ben Cousins.
I think Hagan and Johns had a good relationship, closer to mates than to coach and player, and I'm sure he has done no wrong by him.