I disagree. Racism is about outcome at least as much as intent, and probably a lot more. If I "accidentally" make a racist comment, the fact that I did so out of negligence in no way excuses or even softens my actions. That is, functionally speaking, there is no difference in outcome between killing a person via intent or negligence. The person is still dead, and it in no way comforts the surviving family that the death was simply due to negligence than murder.
That's why cultural sensitivity classes often focus on bringing one's own negligence of racial matters to the surface. Having gone through it in the past, I know it can be a highly unpleasant process. But afterwards, if you let it take its course, your eyes are opened to truths that you had been blinded to all this time.