Actually, calling it a "dumb analogy" isn't an ad hominem attack. Saying "you're dumb so the analogy is worthless" would be an ad hominem attack. Calling the analogy dumb is perhaps not the most polite way to word a refutation, but it is an attack on the argument, not the person.My point was to say there are ways to argue against a poor argument without ad hominem, no more, no less.