The "doing nothing" strategy is interesting. A lot like my bro told me when dealing with his separation. Just laying low, he called it "playing a bit dumb", meaning not to assume too much, not to go digging, sometimes "not to notice" certain things. I guess it lets W. have more sense of control and takes pressure off of both people?
I see what you are saying about the deceptiveness and trust part, regardless of who was over with her. Rebuilding that trust is really important, but a slow process, and I guess she's the one who needs to rebuild trust. She really did seem to want to be clear that it wasn't "what you thought" and often comes forward with more warmth/caring/contact after something like this.