When stbxH moved out, it was already 6-7 months of craziness, hostility and mysterious behaviour (we all know now why...). The day he moved out I was devasted because my kids were crushed. As days passed by, I realised all the emotional abuse I was putting up worrying that me standing up to him would push him away... Now, I wish I had kicked him out immediately. Maybe it would have shaken him up and made him think. Of course reading his mails with OW, he was so deeply in love with her, it probably wouldnt have made a difference... But I digress as you guys say.
My point -lost in the way- is that sometimes separating, is the ONLY way to make harsh feelings fade and allow partners to miss each other. So, it could be a nail in the coffin, but it could also mean that someone may wake up soon.