That should bother you, rather than being the coup de grace you're taking it as. Does it not trouble you that Matt (and others) were auditioned? Doesn't it make the whole "we're filming him secretly, he has no idea what's going on" a bit of a lie? Once he's specifically auditioned for Derren, the fact that Derren then appears in his bedroom isn't perhaps the surprise it should be. A Derren fanboy is then just gonna go along with everything as he should. Doesn't it all seem a bit pointless, watching a Derren fan act out stuff that his idol wants him to? There's no subtlety, no suggestion, no trickery... just, nothing.