I got to thinking about this some more. I really want to applaud your decision to walk away and do nothing. It took me a long time after I divorced not to react to every little crappy thing my XAH was doing to our kids. I now apply the three C's and move forward, allowing them to see him for what he is. Instead I put my focus on being there for them and helping them be stronger people because unfortunately they will have to deal w/their father forever.
So...another big support and applause for you!!!!! Well done!