... I didn't wanted to go any further with this talking to him, since he was becoming very annoying and cocky and I was getting pissed off.

This is an old debating trick. If you look for it you'll see it in all sorts of forms. The basic form is

A isn't a real B because of X

where X is usually something vague, obscure, or ill-defined. If the target of this technique (i.e., you) is embarrased about the prospect of seeming ignorant about X, then the burden of proof shifts from the claimant to the target.

Nine times out of ten, countering with "How do you justify X as a criteria for being a B?" will make the claimant back down or go away, though you have to watch out for parting shots that attempt to paint you as ignorant. If they don't back down, you can often navigate them into an increasingly narrower definition of B.

Try this:

"Tens of thousands of professional programmers use Perl every day. They think that it is a programming language, and they are getting real work done with it. If, for one example, the census department is happy crunching information using a non-algebraicly provable language, what does that say about the appropriateness of 'algebraicly provable' as a criteria for distinguishing what is and what is not a programming language?"