He maybe kinda thought, 'if you leave the WT cult you can do anything you want - cheat on your wife with prostitutes, anything!'
I think he's surrounded himself with lots of people who believe that. They seem to believe that to truly reject the WTS you have to reject all that the WTS ever say. Like-people are often attracted to each other.
Sensible and mature people know that working on your marriage, being moral, being honest, not being abusive and similar things transcend any religious beliefs and edicts - they are simply good things to do if you are a good person.
You don't have to live opposite-life to be an exJW. You don't have to become a drug-taking, cheating, abusive jerk to show how wrong the WTS was. Who says something is irrelevant to the value of what is said. Some of what the WTS teach when it comes to lifestyle is sensible and good. Just because they repeat it doesn't make it wrong. In fact, if you want to show how wrong they are, you should aim to become a better person than the JW version of you.
But to be fair, from everything I've read about him it sounds like he didn't change when he left - he was already a wife-cheating sex pest while he was a JW and that's why they kicked him out.