Yes, during the MLC they lose their sense of self and also their sense of who YOU are--you become everything they need to rebel against: the mother, authority, the source of their misery, and they hurl accusations accordingly.
When my H came out of his MLC, it was as if he saw me again as we'd been when he met--he reminisced a lot about the early days of our relationship, and treated me as he'd done then. He had a lot of trouble believing he'd said most of the things he'd said while he was angry and in the tunnel. This was also hard, because I'd wanted him to apologize and take things back, but that's not where his head was right then.
I know that your H's behaviour is causing you a lot of pain, and I can feel the sadness in your writing. Perhaps read the resources on detaching again: I always found they really helped. And do something loving for yourself.
