I agree that it was a normal pistol with a normal suppressor, but that is about all I agree with.
First off, it was not 7-10 yards, more like 7-10 feet. First shot. See the smoke coming from the ejection port.
Then I do not think the rounds came out as he states. There on the video, you can see that he pulls back on the slide after each shot AND has to tap the slide back into battery.
After the first shot he racks the slide twice before it fires the second round.
After the second shot, starts walking towards the victim and he racks and taps the slide into battery at least twice. He actually fights the slide while he is walking towards the guy.
You can see the recoil on the first and second shots. You can see the attempted shots when the gun malfunctioned and there is no recoil. That is how you know he did not realize the gun did not eject and feed.
Here he takes a third shot and you can see the recoil. And then he again messes with the slide.
But I do not think he makes a fourth shot as he is just walking past the guy and then walks in front of the SUV that has its lights on, crossing the street.
I don't buy the argument that he is a professional since he seems calm. Once he has made up his mind that he is going to do this for emotional reasons, a calmness comes over a person and they act out the plan.
That is my thought on this. He did not have a booster in the suppressor.