[But I will not exempt the late Dr. from legitimate and reasonsed criticism of his actions: victimhood does not equal sainthood.]
The problem for those who would hold O'Reilly accountable is that the same strictures they'd think about applying would have prevented this, this, or even this [which is all that's left of this] from appearing.
Invoking the power of the State in any guise to stifle political discourse--no matter how nauseous--is anathema to the American Constitutional system of government.
And in the words of Anonone:
Violence comes more often from the oppression of speech rather than the free exercise of it.
A free society entails risks. A society without risk is not free. Tough questions like this are where you come down on the side of freedom or security as paramount.