That’s part of his standard bag of tricks. Say loads of ridiculous offensive threatening stuff. See what sticks with his base. Let the sycophants around him laugh nervously but not explicitly say he’s joking unless he does first. He’s only joking when it suits and not joking when it also suits.

Henry Hill: You're a pistol, you're really funny. You're really funny.

Tommy DeVito: What do you mean I'm funny?

Henry Hill: It's funny, you know. It's a good story, it's funny, you're a funny guy.

[laughs]

Tommy DeVito: What do you mean, you mean the way I talk? What?

Henry Hill: It's just, you know. You're just funny, it's... funny, you know the way you tell the story and everything.

Tommy DeVito: [it becomes quiet]

Funny how? What's funny about it?