Despite my earlier comments, I didn't think that the interview was THAT bad either.
The thing is Chris Rock has every right to be tired (or just not in the right frame of mind to be up for entertaining people) at any time of day, and criticising him as soon as he has left the room, when he has no comeback doesn't seem fair. (or the kind of thing that should be happening on national radio)
Fair enough he is getting paid to be on the show, but on air I thought he was polite and quite funny at times...
In any case the show is run by Chris Moyles, if he doesn't think an interview is going well then he should be flexible / adaptable enough to think on his feet and work with the guest that he has got.
He shouldn't go into a bad mood and start criticising the guest (or their entourage) when they have left the building/room(at least not on air), (he probably realised it has just been a bad interview and unfortunately his reaction is to blame the departed guest)
Anyway, on-air criticism of departed guests seems far too one-sided.
If they are going to criticise the guest, then either do it off air, or record the entourages' comments and let the listeners be a party to the whole thing. (I'm no fan of rude people and hearing some pre madonna complaining to the backroom staff would probably make good radio. )