Telling someone to educate themselves and that they can just google whatever thing you're talking about is about as uncivil as you can get before openly insulting them.
When someone comes around demanding that others provide them with information they can easily look up themselves, I don't see the problem in countering that with a politely-worded retort reminding them that they have agency in their own education.
I even pointed them in the right direction with some suggestions.
How would you have handled it?
I'll admit that I can be guilty of speaking from personal authority/experience in forums and not feeling the need to provide references, because it's just a forum on the Internet and there's a limit to the effort I'm going to put into a discussion with strangers, but the other side of that is valid and there's nothing wrong with asking for receipts if you're skeptical...
In the end I am realizing I mostly took exception to the tone of the other person (not the demand itself), and that's on me.. I should have just ignored him and moved on. Not everyone knows how to communicate properly.. Even now he's responding to my other comments (and even jumped into this thread) to antagonize further.. oh well.
TIL 'please give examples/evidence' === demanding.
You're so dishonest and insecure it's hilarious.