Marion, since this is your thread, I'll leave it to you to reveal the name of the famous fiddler if you see fit. I didn't see that particular workshop, but from your description his identity is pretty clear. Apart from being a fine musician, he is also famous for being a jerk unfortunately. In fairness to him, though, he seems to be trying to live down some of his former excesses. He played some great music instead doing yet another variation on his "everybody look at me being an asshole" theme.

What he did in the workshop was probably more thoughtless and immature than genuinely contemptuous of the other musicians.

Edmund