It is our job to look inward and to try to figure out how to be the best person we can be. And while it is important to listen to what your xh is saying, you need to whittle out what rings true and what has no merit.
Remember that he is in a life crisis so his view is skewed. You see, he knows he is hurting and cant figure out why. So, he points to the person closest to him. When that doesnt work, he will try something else. All with the hope that the pain and confusion will go away.
He needs to look inside and do the work. You need to let him.