Narrative cohésion? The tomatometer is erring. In only one short film, there is only so much that can be shown. The film does go through quite a bit of material and there are still secrets regarding this assassination. So, the film could not go into details it did not know. I think we get a different viewpoint. There are still a lot of questions unanswered. The biggest being, who killed JFK? His brother thinks he did, and is maybe even proud of it (according to footage not seen in the film), but in the film he supposedly is not aware he was a spy (failed maybe, but still, still... useful to take the blame for the real killer(s)). He said he did not know his brother after they met in jail. Lots of other things want to suggest the official version is accurate. However, and that is funny and/or telling, at the end there is the usual statement that this is fiction and any ressemblance with actual events or persons is unintentional. Sounds like spin of spin. Or spin to the square.