I have experienced things like this with some Dommes, although not to the extreme described here. Outside of, and even at the end of sessions, they are extremely warm and friendly. But, during a session, they put on their "Domme Suit” and are cold, distant and somewhat angry.

I chalk it up to them sort of role-playing who they are as a Domme because that allows them to get into the head space that works for them when they play. Some guys want and even need that type of personality in session but personally I hate it and thinking I f'd up and caused it does destroy my headspace and enjoyment of it.