Yup, Cluin, I know it's a way to "come full circle" (like repeating your thesis statement at the end of one's term paper).... sort of... except that these comedians don't really go back to the point they started from, just to something from a sketch in the first half or two-thirds of the routine. And the style doesn't really "close" the routine in the sense of wrapping it neatly or buttoning it up snugly. It's more like a knot that has been tied in a rope: they take the end, stick it through a loop in the middle, and give it a quick jerk.

Don't know who James Burke is, but if he was an innovator of this style, then IMO he's been imitated by too many others! Ah well, since everyone is doing it, pretty soon someone will come along with a different innovation, and everyone will follow that for a while until audiences tire of it (and it drives me crazy in the meantime), etc., etc.