I think his argument is that the explanation offered by the author is implausible. When someone comes forward with such claims, the main means of determining it's veracity is to verify the details provided. Typically fabrications will contain small inconsistencies that don't match facts known only to investigators, verified witnesses, or experts in the subject matter.
I think their implication is that none of us really know what happened, much less the author of this article.
I think their implication is that none of us really know what happened, much less the author of this article.