My Guilty Conscience Drying on the Line

Around New Year's I'd gotten an email from a 'friend' (I say friend, but
we've never met --only talked via email through our university system) voicing
her concern that her husband may be cheating on her.  Yesterday, she found
out for sure and he's left her.

And I don't what to say, except to swear a bit.

I have to feel guilty, of course, because I came so close to being in his shoes
nearly a year ago now and I have to be happy that it never got that far. 
And, yes, it would've been my fault if everything fell apart.  Yes, there
was a slight chance that something might've happened over the summer, but I was
too leery at that point and (almost) knew enough to back off completely --kind
of like I have now.

Phew.

The guilty feeling remains and now I have to think about how a similar thing has
affected a friend.

This sucks.