Gary Cornwell was the Deputy Chief Counsel for the House Select Committee on Assassinations. In 1998, he published his book, Real Answers, about his work on the HSCA.

Here is an excerpt from his chapter on Oliver Stone:

"If it can be said that the Warren Commission acted irresponsibly in telling us that there was no conspiracy without having the any real factual basis for that assertion, wasn't it just as irresponsible for the New Orleans District Attorney to prosecute charges of conspiracy without any substantial evidence of criminal culpability? And wasn't it irresponsible for Oliver Stone to try to convince us that our government leaders engaged in treason and murder by fabricating events and presenting them in a way to given them false credibility.

My point, however, is not simply to criticize. Since this, hopefully, a book about history, the real question is, can we learn something from the movie about what causes such irresponsibility -- maybe, even something about what has generally causes such irresponsibility to plague the search for real answers in the Kennedy case for the past 35 years? Actually, one of the best reasons to watch the movie is for the great insight it provides into this issue.

What the movie reveals is the corrupting influence of the loss of objectivity. As portrayed in the movie, District Attorney Jim Garrison vividly illustrates the intensity of feeling that so often consumes people who become involved in studying the Kennedy case, and the distortions in perception and aberrant behavior that such intensity seems to produce. In the movie, Garrison quite simply became obsessed with the case. His wife told him that he loved the case more than his family, but it went far beyond the case merely taking Garrison away from his family. His obsession caused him to lose sight of his responsibilities as a lawyer, and in his quest for real answers, he lost sight of the value of truth. His obsession started, as if often the case, from realizing the undeniable fact that our government clearly botched the original investigation in 1963-64. From that realization, grew a mind-boggling array of questions, issues, doubts and, eventually paranoia and loss of perspective -- all of which was (perhaps) predictable, if not inevitable, and (unfortunately) not unique, for what happened to Garrison is only distinguishable in degree of magnitude from what has so frequently happened to those who study the case.

How could our government do such a bad job, and what in the world could have prompted them? In the end, Garrison went off the deep end. Garrison became obsessed with the issues, and after his principal suspect, David Ferrie, mysteriously died in the middle of the investigation, the lack of evidence of an insufficient deterrent to keep Garrison from proceeding to trial. As so often has happened to others, Garrison succumbed to the temptation to fill the void in real answers with his own pet theory. (He lost sight of the need for evidence to play the central role when he wrote the script for his play.)

In the end, at a meeting in his home attended by Garrison's wife and staff members, Garrison tacitly admits that he has insufficient evidence to convict Clay Shaw of any wrongdoing, but rationalizes his conduct in prosecuting Shaw as the "first step" to bring the truth to the attention of the American public "even if it takes another twenty-five or thirty years." Then, in an eloquent closing argument to the jury, Garrison espouses grand notions of justice, artfully uses unanswered issues to paint the deeper specter of conspiracy, and decries the public's inability to learn the full truth. But the closing argument reveals as much by what it did not include -- any description of evidence showing that Shaw was involved in the assassination -- as by what it did include. In his plea for the jury to focus on the higher ideals of truth and justice, Garrison simply lost site [sic] of the fact that his own prosecution lacked any justice, for it was devoid of any real evidence that the defendant Shaw was involved in the assassination of the president.

The movie excuses the fact that Shaw was prosecuted without evidence, by portraying Garrison as a brave crusader who fought against insurmountable obstacles created by the federal government, and who is worthy of our esteem as "the only man who ever brought to trial any charges in the Kennedy case." In the United States, because of our faith in the jury system as a means of "resolving" issues, we are often not satisfied until we receive a "concrete" or "definitive" answer in the form of a jury verdict. We also tend to admire those who provide us with that satisfaction -- the lawyers, the judges, and the juries who render those answers -- whether they are truly worthy of our admiration, or not. But Garrison proved nothing by bringing to trial a case that lacked substantial proof of actual complicity on the part of the charged defendant, and there is a difference between fighting to expose wrongdoing and bringing unfounded criminal charges.

In a tag line at the end of the movie, Stone reports that "In 1979, Richard Helms, Director of Covert Operations in 1963, admitted under oath that Clay Shaw had worked for the CIA." The obvious suggestion was that this admission proved that Garrison was on the right track, if not totally justified in charging Clay Shaw with killing the president, but in reality it was simply more innuendo, completely devoid of the kind of substance that would justify any conclusion about guilt or innocence. It was simply more of what Garrison's closing argument, as well as the movie itself, consisted of.

Just like Garrison's argument to the jury, what this tag line tells us about the movie comes more from what it did not say, than what it did. If Stone knew what Helms testified to, why didn't he tell us? Why didn't he tell us what Helms said about when Shaw worked for the CIA? Did Helms testify that it was during the summer of 1963 when Oswald was in New Orleans, or years earlier? Did Shaw work as a CIA employee, or was he only an outside contact, someone whom the CIA periodically contacted and secured information from? For what division of the CIA did he work, and on what projects? Did Stone omit the details of Helms' testimony because those details did not support his premise (or Garrison's prosecution theory) that Clay Shaw was working for the CIA in the summer of 1963, and that whatever he did for the CIA had something to do with his contacts with Oswald, and that the "something" in turn was connected to the assassination that occurred a few months later?

Maybe Stone decided that these details are not important. But if these details are not important, then he is obviously asking us to believe that the mere fact that Shaw worked for the CIA -- at any point in his life -- makes him presumptively guilty in the assassination of President Kennedy (and if that is his logic, then perhaps he also believes that everyone who has ever worked for the CIA is presumptively guilty of killing the president). Or maybe Stone decided that even though the details of Helms' testimony were not helpful to his theory about CIA involvement in the assassination, Helms was lying about the details -- you know, that Helms had given a "sanitized, half-truth" in his sworn testimony -- so it was O.K. for Stone to just give us the "good" parts of Helms' testimony!"

And what did Helms testify to? Here is his exact testimony from 1979:

I spoke to Gary Cornwell in June 2020. He said there was "never a shred of evidence to support Garrison's case against Shaw." He offered to help Oliver Stone. when he heard he was making a movie, for free. Stone told him they didn't need his help because they already know the story. He felt that Stone's movie was "great" but "outrageous, the 'deep throat' guy was a lie."