When I go shooting my Smith and Wesson 38, it's loud, and I always wear earmuffs. But, imagine how much more startling the sound would be if you weren't expecting it. Doesn't it seem like Fritz should have at least looked startled by this point? Isn't a person's reaction to a loud blast instantaneous? How long did it take the sound to reach his ears?
Next, I want you to notice "Ruby's" location. He's pretty far away from the cops. Pretty soon, he's going to be surrounded by them, and I mean surrounded by them to the extent that we can't see him at all. He is going to disappear amidst them.
But, do they go to him, or does he go to them? He goes to them. It's not as though he stands still and they get behind him. You see where the car is, and the cops never get near it. What happens is that "Ruby" goes to the cops. He dives towards them. Now, why would he do that if he was supposedly resisting and fighting them? And what would be the point of fighting them anyway? Obviously, he wasn't going to escape or prevail. The most hardened criminal in the world would give up at this point. He might even say something like: "I give up." Because: what's the point of getting beaten up? If you're going to be caught anyway, you might as well go peacefully and save yourself the bruising. And if he did that- said or signaled that he wasn't going to fight them- surely they would have sought to cuff him immediately, which would have ended the scuffle once and for all. But nothing like that happened. Instead, he dives into the cauldron; they surround him in an attempt to cover him up, with one guy actually putting something over his head after his hat came off, and even though at that point he wasn't fighting them at all, they still wrestled him into the building rather than stop and cuff him.
What I am saying is that they were working together. "Ruby" and the cops were working together. They had a common goal, and that was to scurry him into the building and out of sight as quickly as possible and without exposing his face to the camera. That's what it looks like they were doing. That is what they were doing. And they did that because he wasn't Jack Ruby.