I don't actually agree with this part, if only because "ninjas lie" being a fact doesn't make it a good thing. It might be better to say something like "I don't think that's exactly what I said, what I said was ..." and rewrite the statement to be more in line with our cover story. Or deny it outright, who knows?
How about, "If someone calls us on conflicting details, blow it off or deflect or admit, 'maybe I did say that' and move on. The important thing is not to get flustered about it or act embarrassed about being caught in a contradiction."