Don't ignore Rather Your comparison is apples and oranges A person who gets to watch the film frame by frame has an extraordinary advantage over someone seeing it only in real time, and one time only Not to mention Zapruder does say the early frames are missing
Yeah, Rather. The guy who saw the film then got it spectacularly wrong 20 minutes later. Zapruder, by the way, saw the actual event, plus seeing the film in 1963. If anyone would have noted significant discrepancies, it would be he.
Now, as to Zapruder thinking there were frames missing, is that something he said, or something someone said he said?