I think it’s important to remember that “eccentric” personalities can belong to either honest or dishonest individuals.
The question is not whether Stone is eccentric or mainstream in temperament.
The question is whether he tells the truth.
From the Google translation of this page: http://www.rtl.fr/actualites/info/international/article/kennedy-le-reve-a-ete-assassine-avec-l-homme-dit-giscard-7767111282
Valéry Giscard d’Estaing
“Gerald Ford (President of the United States from 1974 to 1977, ed) was part of the Warren Commission, takes Valéry Giscard d’Estaing. I did a drive with him once in the United States, he was President . President and I was myself I told him: ‘I ask you an indiscreet question: you were in the Warren Commission, what conclusions did you come?’ He told me: ‘This is not satisfactory, we have reached an initial conclusion:... It was not an isolated crime, it was something organized We were sure it was organized but we have not been able to discover by whom “.