I haven't watched the video but read about it. There seems to be a common theme in a lot of these instances. People get stopped for minor things, don't follow the officer's orders and things escalate out of control quickly. I don't know if it's happening more than it used to, or if we're just seeing more of it because of video cameras being so ubiquitous. Part of me thinks that this isn't unusual, but that what has become unusual is that the police report of the incident isn't simply taken as gospel because there is competing video evidence.
Honestly, cops routinely violate people's civil rights in traffic stops. You can do everything that you have a legal right to do, and not do things you have a legal right not to, but they will sometimes go batshit because you aren't obeying their every command. Even those that they know they have no legal right to make.
My personal thoughts are that there might not be enough screening in the first place, and then perhaps not enough continuous screening for things like PTSD and such. I've never been a cop, so I can only imagine what they deal with every day, day in and day out, and I can't imagine that eventually it doesn't have an effect and lead to things like this.
In front of the cop is not the place to stand up for your civil rights. Let the situation play out, follow the orders, and if your civil rights were violated and you capture it, file charges.