I think they are designed specifically to not tie to the episode so they could be lopped off for syndication.  I didn't remember any of those little bits until I started watching the show again on DVD.

Captain America…Superman…who's next?
I'm sick and tired of these lazy comic book writers having characters renounce their citizenship just to get a boost in sales, only to have them re-citizenize a couple of months later after the spike's over. How can I be expected to keep track of character citizenship continuity…