Why can't there be a number 3 or 4, for possibilities? 3)He could be fine, was looking for an out, albeit now has gf as reason? 4) she doesn't harbor resentment in future because in trying to play it cool, it was eating at her and she was glad he cut off communication?

I've been on the severe accusation level as you. Even eye contact was taboo and guilt/ shame inducing.

I've been the best friend hearing all marital then relationship ups and downs of a man, before.

So long as the OP, heads to the future eyes open, meaning aware of her own conduct, not seeking and assuming trouble, she may be fine.
There are, at times, toxins to relationships. ..
Sometimes, it's not ok to invite uncle bob to the home, without other relatives or until his behavior isn't creating strife, as an analogy...

Not all women and all insecurities are similar to your wife