It's hard to know everything about pokemon. There are over 700 pokemon, probably almost 750 if you include all forms of everything, I think it's almost impossible to know everything about every one of them, so I don't mind however much or little knowledge someone has on pokemon. There are no barriers to entry for being a pokemon fan. If you're a pokemon fan just because you think pikachu is cute, that's fine by me. For me, knowledge doesn't dictate fandom.
I guess your point was that your buddy was trying to talk like he knew what he was talking about when perhaps he really didn't have a clue. But maybe give him the benefit of the doubt, maybe he just had Charmeleon and Dragonite confused. It might seem like a silly mistake to make, but we all have those brain farts where you get things confused. Even if it wasn't an slip of the tongue, I think most people can also relate to bluffing knowledge on a subject in social situations. Be it politics, sport or whatever, I'm sure we're all guilty of the cursory 'oh yeah' in response to a topic we have no idea about.
As for the actual question, I remember getting into a little argument with my friend about whether Charizard could learn Fly in the gen 1 games. He was adamant that he did because he taught his Charizard Fly and he only ever played the gen 1 games, while I was sure he couldn't because I can remember thinking how it was absurd that he couldn't learn it. Well we looked it up, and it turned out we were both right in a way as he could learn it in Yellow, but not Red of Blue.