That's right- to be more specific Basel German- in each Canton in Switzerland (even among the German-speaking cantons) the language is slightly different. That is, if you take a bunch of people- one from canton Zurich, the second from canton Basel, the third from canton Schwiz etc, they would be able to understand each other, but the accent is slightly different and so are some of the phrases.
There is also a lot of adversity and rivalry between the Zurichers and the Baselers. I am now visiting in Zurich and sometimes when I'm with one of my friends here and we are sitting next to a group of people, a lot of the times they will tell me "oh, that person speaks Basel German" in a condescending manner and make a dissmissive gesture with their hand.
I remember the interview last year when he lost to Mantilla, it was conducted in French. Well he lived in the Suisse-Romande (French part) for 2 years as a teenager, so he had to learn French to survive.
He just has a basic mistake he repeats every time with conditional phrases of the pattern: If I had done *** I would have done ***.
Instead he keeps saying: If I would have done *** I would have done ***.
But then again, I'm not sure how many english-speakers are aware of that...
My german was once corrected by an american,who had lived in Germany.
Even so he was right about my mistake, very German would have know,that he is not a native German speaker,because almost all Germans say it wrong - sounds nuts,well it is
The world is full of nuts,hand me a bowle