N-word Shouted At Palin Rally In Des Moines

Sarah Palin seems to hesitate a bit after the supporter's slur, indicating that she heard what the person yelled. But she just goes on as though nothing had happened. Given the frequency with which this has been going on, it has become obvious that she has no interest in expressing disapproval.

So what reason do we have to believe that she actually disapproves at all?