There is definitely brass hitting the ground and walls, take a look at his ~eighth shot from the semi-auto shotgun: the round bounces off the wall and hits the wall next to it. Even the video you showed when he aims down the street you can see some of the brass collecting on the ground. It is not clear what you are trying to prove, but he drops several things throughout the video that can be seen clearly; flashlight, magazines, guns, etc. Plus, the shots appear consistent with bullet strikes, is there some dispute about real bullets, when he shows the magazines there are standard full metal jackets in each mag that are visible. One thing that could be disputed is if this gunman was under some kind of external influence or motivation.