I went back and looked at several sources of the footage. Correct me if I'm wrong, but it looks like the first shot was a miss low right as he got too focused on his phone to bother aiming. I also noticed that, despite other comments on this post, you can see the slide moving into battery. As for the reaction time, I've seen an RPD burst fly within inches of dudes skull with zero response. Human behavior is odd in stressful situations. It's part of the whole OODA cycle; sometimes it takes a bit to get past observe and orient. Finally, everytime the footage gets re-uploaded it becomes less and less reliable. I wish I had saved a copy when it first happened.