It wasn’t for real, you could see Letterman was trying to get him to laugh and he almost did a couple of times.
Look, for his mental health, I hope you’re right. I’m not at all certain you are, but who knows.
The Unabomber line almost made him break character. He ‘got’ that Letterman joke and almost laughed. I agree with you. PR Stunt.
he smiled at the very end
hard to tell if that was for real or if he was taking a piss (Brit term)