As much as Tom Smothers is usually upbeat and funny, in this "behind the scenes" appearance he is shockingly serious. His extreme dislike of Penn Jillette is palpable because Jillette had recently appeared on radical far right wing Glenn Beck's show, and expressed a sincere affection for Beck. In their few direct interactions, Smothers does nothing to hide his resentment that Jillette would make any effort to justify Beck's extreme views. Jillette realizes Smother's disdain and plays off of it. Which only infuriates Smothers even more.
It's been over a dozen years since I saw this show, and my recollection may be a bit fuzzy, but the fact I remember it at all is notable.
