Several years ago, I noticed that once he hit the floor, Oswald was lifted up by Jim Leavelle as he is struggling to stop Jack Ruby from shooting Oswald a second time. I focused on Oswald in the films once he disappeared from view, and saw that he was raised from the floor during the scuffle.
I notice, upon seeing the enhanced videos included within this post, that Jack Ruby (after being lightly struck by the vehicle that's back into place to carry Oswald across town) appears to lose his footing with his left foot as he hurriedly begins taking another step towards Oswald. I also noticed that the coat tail on Ruby's suit coat can be seen against the tail light of the car as it's backing in. I also noticed that Oswald's feet completely leave the floor, once he's shot. I also notice that Ruby's gun, still in his hand along with the hand(s) of L.C. Graves, can be seen between Grave's legs from behind Graves as Grave's is trying to remove the gun from Ruby's hand.
Just my own observation.