In short: There's telling a joke, and then there's going too far (be it deliberately or accidentally). In this case, he didn't know the consequences and went too far. I can understand that he wasn't intending to hate on Jews or anything of the sort, unfortunately: The majority of the world doesn't take too well to casually joking about Hitler or the Nazi. If he had chosen something else to annoy his girlfriend (which was apparently the original point of the video), perhaps he would've fared better off. But it didn't go that way: So now, he has to face the consequences.