When it comes to whether it was really Jack Ruby who shot Oswald, I hope you realize that it's determined by the images and not by anybody's lip-flapping.
When you look at that and see that it's two different heads, you know it's two different men. And that's true regardless of anything else that anybody says. This trumps it.
And what it comes down to is putting reality- that which you can see, feel, touch, etc.- ahead of gibberish, ahead of noise.
The images rule. The images slap-down the Ops. Know what matters. Know what takes precedence over what. This takes precedence over everything. Anyone who tells you that this doesn't matter is telling you to pay no attention to the man behind the curtain.