First, arguments should be with individuals who would see reason and be able to condone the defenses of the other party. These are the kind of arguments you put your efforts. This was your first experience of him and overtime, you understood he was not worth the hassle. Thankfully, you didn't result to exchange of foul language or abuse.
He had a taste of his own medicine, needing the presence of a woman desperately in his life. We can do many things but not all... That's the state of life and living. Thank you for sharing.

I hope he finds succor to his financial and child care