I think what you must keep sight of is that whatever you do with Mr. GAG as far as DB'ing you must have NO EXPECTATIONS.
That is part of DB'ing. I think you have been nicely paving the way with him, but he is still in crisis. And this event is an unknown with him, the MLC'er must sink to rock bottom before they start back up again. It is never smoooth and easy no matter what we all do.
Grieve her loss and help Mr. GAG through this time also. Later down the road you can see what it all means. Not now, it is too soon, too raw.
Everything you are feeling is OK, you will be fine and I am sure you will keep DB'ing because once we learn these skills we never let them go.