Here is Leavelle before he turned:
Now below, here he is a split-second later, just when "Ruby" is making his move.
And note also that that look to the right isn't even a probing, scanning look to the right. It's just an evasive look to the right. It's not as though he's trying to see anything on the right; he's just trying not to see something on his left. If you look closely, you can see the Fedora hat peaking out above. "Ruby" is in front of the man with the camera to his eye. Leavelle has turned his head to the right. And Leavelle did that an instant before "Ruby" began to rush in.
To me, it has all the earmarks of Leavelle knowing what was about to happen and diverting his eyes- because he had no intention of stopping the man who was going to shoot Oswald.
And think about the preposterous thing Leavelle said about it afterwards: that he saw Ruby, and he jerked on Oswald to get him behind him, to shield him, to protect him- all totally and completely bogus, a bold-faced lie. He did nothing of the kind. And, it's all the more reason to see it as I see it: that Leavelle knew before he stepped out the door what was going to happen.
Supposedly, Leavelle was there to protect Oswald. I don't think anybody was afraid that Oswald was going to make a break for it. Oswald was cuffed to Leavelle, so there was no chance of that happening. And, as I've said before, there was no chance of an attack coming from the right side. IT WAS LINED WITH COPS! And they were described as a "police guard": more protection for Oswald. So, if Leavelle was going to look anywhere for trouble, it should have been to his left- the direction from which "Ruby" came. But instead, he looked to his right. Leavelle did NOT want to see Ruby. He did not want to react to Ruby until after Ruby got the shot off. And that is exactly what happened.
You should watch this video again. Start at the 13 minute mark. Once Oswald gets shot and goes down, "Ruby" dives into the circle of men, then, somehow, they swift him away- right into the building- without ever standing him up and cuffing him. Another swarm of men come out of nowhere, some in police uniform and others not, who block the view and put their arms out to prevent entry into the space. And by the time the space clears, it's all over. "Ruby" and the men who were restraining him are gone, and presumably they waltzed him into the building.
In real life, nothing like that would have happened. What would have happened is that they would have sought to cuff "Ruby" immediately, and once he was cuffed, the struggle would have been over. He'd have been pacified. And then they would have stood him up and walked him away in plain view. But, that didn't happen here. It's more like he just disappeared; vanished; like a magic trick. And it all happened so fast; first he's there; then he's not. Again: it starts at the 13 minute mark.
Here is Ruby, the real Ruby, a short while later, in handcuffs.
So, when did they put those cuffs on him? And why didn't they cuff him right there in the garage? Why was it better to wrestle him into the building without cuffing him? And was he really resisting? What for? There was nobody else he wanted to shoot. He looks perfectly pacified there. But, to tell you the truth, I'm a little surprised to see his hair combed so neatly if he went through this:
It seems to me that his hair would have gotten mussed, and it doesn't seem likely that he would have had time to primp afterwards.