Also, I don't agree that the context is wholly exculpatory and makes this a complete non issue. He was wrong in using this type of language with this particular audience, even if in a NYT article it would have been perfectly acceptable. He was misunderstood by the teens and seemed shocking to them, despite how he (or I, or you) views his own words. It would have actually been right to apologize to them, as he clearly failed in communicating the nuance he was trying to communicate. That's not to say that he is a racist! But he obviously misjudged his audience and caused them more harm than good with his words, even if he had the best intentions behind them. Especially since he was payed to be there and teach them, this is not some case of some teens finding someone's blog and taking offense at what they think is being said there.