The German people rate high on the scale of social development, that is to say, wide deviancy from the social norms of the day attracts the sort of disapproval that most are unwilling to accept. The same holds true for Scandinavia, Holland, and other Germanic parts. Consequently, when presented with a Neger crapping in a train, 99.9% of Germans will succumb to a sort of mental disconnect at what they're seeing, and simply move away.
I doubt the same would happen in AngloSaxonia, where there are always present members of the feral underclass who would be quick to react in an explosive way. Were some nig nog to do the same, in say London, Boston, or Sydney, its a pretty safe bet that he'd end up with his sh1t on his head ?
Its nice to live in a society where things a fairly predictable, and people tend not to be so close to the edge that they react violently. But if you suddenly introduce vast numbers of people who are effectively 'Uncivilised' then big problems lie in wait.