You can clearly see that Leavelle's left shoulder is BEHIND Oswald. It means his left arm also was behind Oswald.
I'll give you the CNN version first which shows the weasel arm but then breaks away from that view. Then, I'll give you this other version which stays with this view, and that's where you see the unaltered frames, although it looks like they may have added some of that black, widening Oswald's shoulders.
Remember, the JFK assassination is the most photographically altered event in the history of humanity.