In reading the latest news articles and the previous statements before the video was released, there are obvious problems with his story. I would HOPE the investigation would have uncovered the descripancies or at least cast serious doubt on the incident. For example; cop says they struggled over the taser after the deployment was unsuccessful. (one prong struck and stuck to Scott) So he then drew his weapon firing in fear of his life, implying the struggle was on going.
However, if it were an automatic (number of shots would indicate so ) then 8 spent shell casings would be near the vehicle, not anywhere near the body. This would present a problem. If his story, when he is getting specific is they were fired in close proximity, there would likely be powder burns on the clothing. Absent that, it should raise flags. Finally, all the rounds striking his back would not support his version. Adding all three of those things together... should indicate to an investigator the events as described couldn't have happened as told. If the department was too incompetent to figure it out, the back up system, which is the DOJ/FBI should have zeroed in on it.
I'm just glad the video surfaced so there is zero chance he skates on it