It’s what he does.Tediously wrongsplaining your own country or culture to you is one of the bad Dr’s signature moves.
Yeah, that’s why I didn’t respond in the thread but took it here.
Yup. That’s pretty much is MO. He doesn’t know something but rather than just keep his mouth shut, he googles it and finds the first answer that pops up. He won’t read the whole cite, but believes he’s an expert and argues endlessly.
So, his correcting you, a native speaker of German is what we would expect. He has zero knowledge but he’s got to say something and then will dig his heels in forever.
Typically, he’ll read a book or article (however superficially) by someone presenting a dubious minority case for something, latching onto it like it’s the undisputed Truth and denigrating accepted experts with ad hominesque insults.
A well-informed consensus is sooo boring.
Well, miracles happen, he just admitted that he didn’t know and learned something new from my correction in the pronunciation thread. Do I get some prize or badge for being the first doper to ever get this from the Doc?
Absolutely!
Oh well, thank you, I’m so grateful for this prize! 
Here’s a real trophy to commemorate your success.
I think you’ve proved that he secretly does read his pit thread.
Don’t forget the other part of his MO: accusing those correcting him of insulting him even when they didn’t insult him, or, and this is my particular favorite, accusing them of insulting his father.
Well, to be fair to him, he may be too stupid to realize his father was bullshitting him his whole life, and he can’t see the impossibility of the stories even when pointed out to him.
Well, no one else knows if he was the one lying or his father, but given his MO, it seems clear . . .
It could be A; it could be B; it could be Both A and B.
What if—hear me out—it’s i (that is, the square root of negative one)? What I mean to say is… what if DrDeth is his own father?
I’ve heard in a song that you can be your own grandfather, but father?
Back in the 80s, when he got in Doc Brown’s DeLorean after the Iranians attacked and hijinks ensued, he couldn’t resist his mom’s charms.
(That’s one way that could have been accomplished.)
If you’re claming DrD is a product of inbreeding… 
That would explain a lot, actually.
Don’t ask me to explain time travel.
Maybe by traveling in time it split into a parallel timeline, and technically it’s not actually his mom?
I’m not a chronophysicist.
The guy in the song becomes his own grandpa when his dad married his step-daughter, which makes her his step-mother, making him his step-mother’s step-father and himself his own step-step-grandfather. So I suppose if one’s father remarried and then died, and they married their step-mother, they’d now sort of be their own step-father?
I don’t know, I’m not a stepologist.
Libyans, I think.
(And isn’t the “couldn’t resist his mom’s charms” hypothesis rendered unfeasible by the fact that Marty has at least one older sibling?)
NM. I failed to consider the possibility that Doc Brown took on a separate assistant (with a similar, though not identical, outcome).
This is 100% my bad.