The reason Tiger was not more upfront about Kelly's comment is because he recognized it for what it was, an unfortunate choice of words on Kelly's part. If she were to say something intentionally malicious he would have been all over it. From a white man's point of view I think there is a small population of blacks that look for a fight, but if they choose the wrong fight it will eventually lead to the 'the boy who cried wolf' syndrome and when  a real issue arises the leverage will be gone.