Your call
So, I checked out "The Zapruder Film Mystery" and was a bit puzzled.
It starts off with Horne expressing his conviction that the Z-film was altered so I expected the interview to deal with that.
However, Horne never once asked Bruglioni about whether he thought the film had been altered. The interview is about two briefing board "events", and that's it.
Bruglioni never expresses any kind of view about whether or not the film was altered and Horne doesn't ask him a single question about it.
At around the half hour mark it suddenly cuts to a different interview between Dino and Janney.
This interview appears to be about a single z-frame, 313.
Dino is talking about the debris cloud from the head shot. Janney begins to tell Dino that frame 313 is the only frame that shows the debris cloud but Dino can't believe it - "there was more than that".
Janney asks - "How many more frames do you think there would be [showing the debris cloud]?"
Dino - "I don't know but we were shocked when we saw it."
Janney is lying.
There are more than just the single frame showing the debris cloud and Dino is perfectly correct that there are multiple frames showing it:

I also noticed that not once did Dino mention [nor was he asked] about Jackie on the trunk of the limo.
In another article Horne claims that Dino saw Hill physically strike Jackie while she was on the back of the car which, of course, is not shown in the extant Z-film.
Hill striking Jackie?
Really?
Why didn't Horne think to ask him about that in this interview? Why didn't Horne even think to mention it, as his sole purpose was expose alteration in the Z-film?
There is nothing - absolutely zero - that even hints at alteration in this interview.
What am I missing here?