Been there with a family member who has a personality disorder (not narcissistic personality, but alot of personality disorders are intertwined) infact still happens occasionally.
Watching that actually gave anxiety. Speaking through grinded teeth, eyes unfocused, unable to string a full sentance together.
I dont think it's an act and I think it's real.
Makes me feel sick because of what it brings back. So much more I could say on the subject from experience.
Anyone dealing with someone (family member etc) with personality disorders I'm here to talk.
I genuinely hope he gets help, and apart of that will be accepting punishment for behaviour.