When I say something untrue on the air, I mean for it to be transparently untrue. I assume people know when I'm just saying something for effect. Or to be funny.
One reason I do the live shows - and the monthly speeches at public radio stations - is to remind myself that people hear the show, that it has an audience, that it exists in the world. It's so easy to forget that.
I think good radio often uses the techniques of fiction: characters, scenes, a big urgent emotional question. And as in the best fiction, tone counts for a lot.