Yes, he's making a joke. It's funny and a pithy remark. The point is made. I find it an interesting point because when mocking other peoples' intelligence on

Yes, he's making a joke. It's funny and a pithy remark. The point is made. I find it an interesting point because when mocking other peoples' intelligence one ought to make certain they are correct. Sort of how when one criticizes another person's grammar they should make sure they didn't make a grammar mistake too.