Where's the part in all that that says "undercover"? Don't forget, the issue isn't that someone said she works at the CIA - there's nothing at all wrong with saying "so-and-so works at the CIA". The key allegation here is that someone apparently said Plame works (or worked) as an undercover field agent for the CIA.
Even if I stipulate everything in your post is true (and I have no reason to doubt you, frankly), you still haven't addressed the allegation.