Here's a TLDW summary for those too lazy to watch the full video of what happened.

Cop driving along. Truck flies by him (he says doing 100, seems about right). Cop catches up to him and flips on lights. Truck keeps doing same speed in fast lane (3 lane road). After a little bit he flips on blinker to get over to middle lane. He stays there for 5-10 seconds then accelerated and gets back in the fast lane. Cop pursues for 30 seconds or so. Truck then pulls over.

Cop surprisingly does not pull his weapon out immediately (most would in this situation). Starts yelling at the driver to get out of the truck as he slowly approaches driver's door. Driver gets out and asks the police officer who he is, tells the police officer that he is Yahweh. Police officer puts hand on man, man aggressively flings officer's hand away. Cop continues yelling at the person to go to the back of the truck and put his hands on the truck. After some more somewhat belligerent talk (in my opinion more drug-addled than threateningly belligerent, the toxicology results will tell) the man complies and goes to the back of the truck and puts his hands on it.

The officer then tells the man to put his hands behind his back. The man refuses, asks why. The officer tells him he's being arrested. The man asks if he has a warrant (?). The officer tells the man that traffic offenses in GA are criminal offenses, and he was driving recklessly. The man continues arguing. The officer warns him that he will be tazed if he doesn't comply. The man continues arguing. The officer tazes the man, who stands still for 5 seconds or so then points up at the sky, then turns around and begins flailing at the officer. The officer attempts to subdue the man, but the man gets the upper hand on the officer and gets him in a choke hold. The officer pulls out a baton and starts whacking the man in the head with it, but it doesn't seem to have any affect. The man, meanwhile, is clearly getting the upper hand in the altercation, bending the officer backward while continuing to choke him and repeating, "Yeah, bitch!" You cannot see the officer pull out his sidearm from the position of the camera but the man goes down and it appears the officer shot him in his left abdomen area. The man continues to rant for a little bit and flail around on the ground. The officer has to keep the man at gunpoint until backup arrives and then tries to assist the EMTs and is clearly distraught at what has happened.

The bottom line is the officer was justified in pulling the man over and ended up acting in self defense. He did not even act as aggressively as some officers would have (having their sidearm already out when exiting their car after the vehicle had appeared to consider fleeing). The toxicology report will almost definitely show the man was loaded up on something, as his behaviour was anything but normal.

Go find some other (more justified) scapegoat to vent your cop hate on. This guy was just doing his job.