I only know his side from what she has told me. I DO understand her side. But I also understand that in order for things to get better OH will need to change her communications with her husband. He is not capable of doing so at this time. She needs to either do the heavy lifting or leave (since we both agree that continuing on the current path is getting both of them no where fast!).
I KNOW HE will need to put more effort in. OH should expect it and deserves it. Heck, she already DESERVES it. But sometimes in life, we don't get what we deserve...when we deserve it.
I KNOW OH is in the RIGHT. I just want her to be happy and to see her marriage survive, if possible. Since she is the ONLY one capable of steering the boat right now, I suggest she grab the rudder or abandon ship.
Logical and simple seem to be in order right now...at least from my perspective. I respect your view and know that we both have OH's best interest at heart.

Don't go shaking the [Bleep!] tree and expect an angel to fall out.

Liars lie and cheaters cheat...know it and don't be surprised. Protect yourself.