Hmm, I don't really remember that. I'd assume they meant that they didn't want to stray into comedy territory the way that particular episode did.
Personally, I've never had the feeling the writers were actively trying to keep humor out. I think they've been careful to use it in the right places and with the right style. It has to fit into the show.
As I mentioned earlier, I find that most of the humor results from the characters or the situation. It's never about telling a joke or making fun of somebody. It's just that people can be very funny in what they do, and I think that's what they're making use of the show.
I think the writers are very observant of human nature, and this is one of the ways in which that shows.
I don't remember specific podcasts but I certainly remember Moore saying (on more than one occasion) that a given scene was very funny in his opinion, and it didn't sound as though that was unintenional at all.
Maybe somebody who knows the podcasts a little better can provide some feedback on this.