Of course we don't know how done anyone is, and we must realize being done today can change tomorrow. He has given you the answer through your son, he doesn't trust anyone, that includes himself and chances are he feels remorse for leaving and is worried what happens if he comes back. Whatever you do if he comes back don't bring up why did you leave right away wait a while to put that beast to bed.
I am sure he wants to be sure, do what you are doing be cordial, warm if it feels right and do things for the kids and yourself. Maybe invite him to partake in some family activities.
Did he leave on his own or did you ask him to?
Married:10 years D final 8/28/08 10 minutes is all it took Life goes on and DB was no small part in growing from the Divorce!