He lied about a bomb on board in the same episode. So you can't count on him for the truth, but that doesn't mean there may not be something big in the clue. However, more clues are pointing to Baltar, especially now that we seem to be told the final Cylon is also a sleeper who doesn't know their nature. (One thing about Lee that is interesting is we've never seen his internal mental state, the way we've seen it for Starbuck, for Baltar, for Roslin and for William Adama, though only to a degree for the latter ones.)