I responded by calmly pointing out the factual errors in his initial assertion, countered with a logical yet extreme extension to his position, then asked him a question that was meant to illustrate one way that he was thinking irrationally.
He sat there confused for a few seconds, until another coworker spoke up. "It's hard to argue with Patti. She's too logical and reasonable."
Hrmm. I'm not sure I agree with her assessment, but it amused me to hear her say that.