I've found that almost everyone who hears H and I are separated assume a divorce is pending too. Even H isn't to the point where he KNOWS he wants one -- he basically said he didn't know that he didn't. People even ask me if I'll be staying in the area! So I think the tendency is to assume that separation = divorce and you shouldn't read any more into your friend's questions than human curiosity and his own musings about the implications of a relationship ending.
You should also not assume that spouses share all the gritty details with each other. They may not, for many reasons. But it was really kind of him to reassure you that you wouldn't "lose" him in the split.
I hope today is a better day and that you have something planned that will give you good feelings about yourself. Hang in there. There will still be low points along the way, but for the moment you're likely on a flat, smooth patch of road and will have some space to regain your balance if you take it.
Best to you.
Me42, H40 D12, S8, S7 A revealed: 7/13 Sep 4/14; Agreed to D 1/15