According to the Interesting Facts page, he went there with a forged Brazilian passport. I do not believe that though. People are very overly suspicious of Korea.
I wonder whether he visited other European countries while in Switzerland. Wouldn't be surprised about France, Germany, Italy, Austria or Liechtenstein. Not a long way from Switzerland.
He went to university in Switzerland, which is why he can probably speak English and maybe even some German and/or French, but chooses to only speak Korean.
$%$&%(&$$&*@#