I'm guessing the OW is involved here. The fact that he answered the phone is good. Perhaps, he is dealing with his "mess", as well as his emotions. Maybe he was on the phone with her trying to calm her down.....she sounds like she could fly off the handle. I know these types of people. He may need a restraining order on her for your family.
You have a right to know where he was and what he was doing. Has he agreed to any counseling?