I think you’re referring to posts by Bluesman, who stated that he was a US Air Force intelligence guy working on WMD and Iraq.
See, for example, his comments in this thread: Bets on when the US war with Iraq will begin?
However, he did continue posting into late 2003, as in this thread, still defending his position that there were WMD:
What’s the betting on the election - can Bush win?.
However, I think that this thread was the last one he posted in relating to this topic.