Actually you don’t. Why are you lying about this?

It’s enough to show that they’re wrong - and if you guess wrong that they are lying, and they were just wrong in good faith, you’re much more likely to convince them (and others).

And, from the HN guidelines:

Be kind. Don't be snarky. Converse curiously; don't cross-examine. Edit out swipes.

…

Please respond to the strongest plausible interpretation of what someone says, not a weaker one that's easier to criticize. Assume good faith.