More on Gaius

At the end of tonight's episode, Ellen Tigh was "proven" not a Cylon. Why?

Six: "If only they knew everyone passes these days."
Baltar: "Well, it's much simpler then. No muss, no fuss."

This adds more support to the arguement that Gaius is not totally honest, consciously or unconsciously, in his intent to reveal the sleeper Cylons in the fleet.