I think it goes both ways. Education is much more useful than just labeling someone a racist simply because they come from a culture where they don't observe the same sensitivities. I had a similar experience when I went to say hi to an American and tried to kiss him on the cheek. He looked like I had just tried to assault him, but men here kiss each other on the cheek all the time. Expecting everyone you meet to know and conform to your cultural standards, especially when there is no malice involved, only impedes progress.
On a tangential note, the other day I was thinking about how cultural differences and expectations cause these misunderstandings, especially when it comes to football. For instance, in British culture, sportsmanship is paramount, while in South America, winning is what matters most. Exaggerating fouls is seen as a bad thing to do, while we consider it smart because it can cause the opposing team to lose a player and, in turn, gain an advantage. Martinez's "shithousing" is another clear example of what many consider going against the values of sportsmanship.
But holding the position that the game should be played in a certain way and that those who don't accommodate that expectation are wrong is, in itself, a form of cultural imposition. Expecting everyone to adhere to one cultural standard disregards and imposes upon the cultural norms and values of others.
Of course, this doesn't apply to cases of racism—just a thought I had yesterday in the shower.