LOL, how true, and actually WS is a pretty damm good narrator, it is indeed gold when he grinds this idiot without insulting him once..
He's a hugely experienced narrator, that's for sure, and he's done an asston of voiceover work. Probably more to the point, when you hire William Shatner to talk about your shit, it's because you want William Shatner to talk about your shit. Everyone knows what he sounds like, and you don't get to try to coach him into sounding like something else. It would not have been nearly so mortal a faux pas if the producer hadn't taken the bait and tried to perform an example take, thereby putting himself into the "observer who thinks it's easy" category.