Irrelevant. It is still just one of many assassination film and photo records, and they all form a self-authenticating whole. You cannot alter one without giving away the whole game.
This has absolutely nothing to do with whether the Zapruder film was altered or not.
Roger, this is nonsense. First of all, why have shooters firing from the front in the first place if you're trying to frame an assassin allegedly firing from the rear?
They have been addressed directly, repeatedly, for decades by the top researchers in this case, the majority of whom reject this fanciful mass alteration theorizing. Given available technology, there is no possible way the Zapruder film could have been altered to the extent some people believe.