belboid
Exasperated, not angry.
Most magicians I know or have spoken to -- no, scratch that -- all magicians that I know or have spoken to think that Derren Brown is fabulous. I am surprised that your fella has such a grudge.
sounds kinda like the attitude of my brother (who writes teenage fiction) towards that Rowling woman - 'no, she isn't any good, her plotting is terrible. No, I'm not jealous of her in any way shape or from.'

He's a love rat magician.
I don't think it helped that they have met several times and Derren came across as quite arrogant. I've never met him so can't comment on that.