As far as I can tell, this is fairly normal for a MLC'er to react this way.
It is the part that is still not sure the right decision was made and they try to cling.
There MAY be a part of him that is starting to know that what happened was wrong. And not neccessarily what he wanted all along.
I also think that you were right to tell him that you cannot believe him. He has given you NO reason to do so.
He needs to reap what he has sewn for it to hit home.
Is it too late ? Probably so. Only you know that....
And although I don't agree with his tactics and superiority complex, I agree that D8 needs to be a priority to BOTH of you, and I know that she is for you.
I know it is hard, but that relationship between them is one that HE needs to find.
In a idealistic setting, he is right. 100% backing is usually required. But that is assuming that your D's best interest is at heart for him.
Trust has to be earned....Find a balance with this.
If he wants his parenting skills backed 100 % ? , then he needs to show you he is 100% commited to doing the best for her at all times......
But you know this.....
Just be careful of the bats flying out of his head.....:)