I prefer the concept of Trial by Jury based upon sortition as an illustrative means of settling disputes of morality with relative effectiveness.
If the cases in question were cases whereby the due process of law was accessed by these three people, and I was randomly picked to be on a jury, I'd find guilt in the form of threats made by the person named Buckley upon both victims those being Vidal, and Chomsky, and I'd call for a substantial fine to be paid by Buckley to those injured victims of Buckley's threats.
I don't think that Buckley would actually get his hands dirty, mind you, but I think that there is a real possibility that Buckley might have hired someone, based upon that threat, to injure, in some way, his targeted victims.
I most certainly can be wrong, and if I were on a Jury in such a Trial, then I'd insist upon discovering as many relevant facts as was possible to be made available to me, before passing judgment, and before any form of punishment was sanctioned by me, as a representative of Free Market Voluntary Government.
Some people confuse anarchy with crime made legal.
I do not.
To me the person Buckley represents crime made legal, and I would never take any threat made by him lightly in any case, knowing what I know at this point in time.
The subject matter between that Liar for Crime made Legal Buckley and the linguist, and the author of novels, was the legal mass torture, and the legal mass murder, of innocent people, and the reason for all that torture, and all that murder is at least two fold, which is ONE the maintenance of a Legal Money Monopoly Power, and TWO, to satisfy the lust for destructive power infesting a few examples of human beings which hardly qualifies as being human.
So, no, I don't think that the threat was a joke, since that joke is no longer on me.
The threats are real, as serous a Nuclear War, in that context precisely.