Oswald in the doorway: the blog of the Oswald Innocence Campaign, by Ralph Cinque

I'd like to make some other observations about the Nix film, since we have it out. 

Do you still think LBJ isn't seen crouching down in the Nix film, knowing that bullets would soon be flying?

You can see how low LBJ is compared to his diminutive wife, but it turns out that Senator Ralph Yarborough was no giant either.

Look at the scowl on JFK's face as he looks at LBJ. That was taken at the Alamo in San Antonio.

I'll also point out that LBJ typically liked to brandish his height. He liked to tower, whether standing or sitting.

Next, it seems to me that Jackie was definitely reaching for something.

If she had been trying to exit, to get away, she would have not been all stretched out like that. If relocating herself was the goal, instead of stretching, she would have gotten her knee up on the back of the car to crawl. But, she looks to me like she is reaching and stretching for something- a piece of JFK's head. 

This is how we first see Clint Hill in the Nix film.

He is on foot at that point, and he has to catch up with the limo. How could he do it unless the limo had stopped or nearly stopped?

The limo does seem to being going slow in the Nix film, much slower than in the Zapruder film. But, did they remove frames from the Nix film to hide the slowing and the stopping of the vehicle as they did with the Zapruder film?   

I suspect they did, and it's because of the speed at which Clint Hill scurries to the limo. He was on the footboard of the car behind. In the frame above, he has already covered some distance, but he is going to go the rest of the way and very quickly. He really scoots. But, how fast could he have gone? It's not like he was an Olympic sprinter. And no matter how fast he was capable of moving, it would still have taken him time to accelerate. Remember, he started at 0 miles per hour. He stepped off the car on which he was riding, but I don't think he took any forward momentum along with him. Furthermore, if the Presidential limo had stopped, the Secret Service car must also have stopped.

In this video, MK Davis demonstrates that Roy Kellerman's head hits the dash when Greer hits the brakes. A body in motion will stay in motion. 

https://www.youtube.com/watch?v=ZLo0_D9h2Kk