Nope. Ambassadors don't qualify as "administration officials". I'm pretty sure I read that somewhere.
Come now, let's parse words, shall we?
Joe Wilson's stock in trade was his vast experience as an "expert" on policy and a former "high ranking" government official (not to mention being married to a wife who worked for the Agency). I'm sure there is a lexicon of amorphous trigger terms used by journalists to try to indicate they got their information from someone like Joe, with "inside access".
In fact, Bob Novak's misuse of the term "operative" to describe Valerie Plame, is a big part of what set off this entire ridiculous rabbit chase to trace the Washington DC gossip circuit.
BTW- I don't think Wilson was Woodward's source. But I think he was a source to most of the rest of the world that he had any opportunity to try and impress..
Of course, in Joe Wilson's mind and with his irrepressible ego. . .