It could just be my imagination based on what I would expect to see. But, I do see some movement going to the left in the shortened segment. It appears to me to perhaps just be a white police officer helmet that is ahead of the JFK limo. I see things better on my iPad screen. I think it is an OLED type screen. Look in the area where I drew a yellow circle. You have to be looking between the vehicles that are going to the right because they are between the camera and the movement that I see. Also, I drew the outline (in blue) of what looks to me to possibly be the shape of Parkland Hospital in the distance. If that is actually Parkland, that would be the direction of travel of the vehicles after they cleared the RR tracks and intersection at Hines.
Charles, I’m mostly replying belatedly to your reply #11 in regard to motion you detected within the area of your yellow circle. I’ve had a difficult time with this area but think now I can see a light colored “blur” appear near that area around frame 094. Frame numbers refer to actual film frames and not the animation frames, which were reduced by about a third due to blur. This object (Green arrow) appears for a few frames moving westward but is soon obscured until it reappears near the end of the film at frame 199 (Blue arrow). The green region may be where it could look like a white helmet in motion, but much brighter than any other helmet in the film. At this time there is a motorcycle traveling maybe 10-20 feet of so ahead of the blur. It is the #4 motorcycle in my previous post above. This blur, at the Blue arrow position, seems consistent with a light colored sedan. I ponder if this may be the lead car (Curry’s). If it is Curry’s 63 Ford Galaxie 500 there is a lot of chrome surrounding the windshield that would be reflective. I believe whatever vehicle it is it is in lockstep with the four cycles ahead of it.
See the two frame toggle animation showing these arrows.