You may be right about the shooter. But listen, I am really wondering if Oswald got shot in that garage. I have my doubts. I don't doubt that he was eventually shot. I have no doubt that he was killed. He had to be killed. They had to silence him. But, they may not have killed him there and then in the police garage. Just consider:
1) Not a speck of blood. Nobody but nobody saw any blood.
2) In the famous Jackson photo, Oswald's left hand atop his chest is false. It was Craig Roberts who first noticed it. It's actually two hands clasped together, as in prayer. They fabricated that hand. Oswald's whole reaction is meant to cover up the area of trauma so completely that we see not the slightest disruption of him or his clothing. Why? Because there was no disruption of him or his clothing.
3) Oswald was shot in left rib cage. The bullet traveled from left to right across his upper abdomen. But, his reaction was to first cringe forward, and then to veer backward, and then to go way up on his toes, and then to fall straight down like a stone. But, reportedly, his aorta and vena cava got severed by the bullet. A person so catastrophically injured would go straight down. He would just collapse.
4) Oswald just vanishes after the shooting. We don't see him being carried into the building.
5) It was at least 15 minutes before he received any medical attention. How could he stay alive for 15 minutes with a severed aorta and vena cava? He would have bled out in less than a minute.
So, I think the odds are very great that Oswald was shot somewhere afterwards.