Non-LEO's think it's so damn easy to hold down someone who doesn't want to be held down. Get three people together and make the smallest the 'bad guy'. Tell him he can start resisting at any point at random. Now, try to get his arms behind him without looking like some of the videos in the protecting and serving thread. It. Ain't. Easy.
This guy had two firearms on him, this appears to be a DUI stop, the guy knew he was in trouble. This guy was on 'something', so whatever it was was blocking some pain. The whole time, he's thinking how do I get out of this? Now you have two cops trying to arrest him. When someone is determined to not do what you tell them, it's pretty hard to do it without brute overwhelming force.
They did drag the guy out of the roadway before trying to finish the arrest, so it looks to me like they still had their heads in the game. It looks like they tried to cuff under power and it just didn't work out for them. They did a lot right in my opinion, it was just too far outside their box to deal with. As much as I agree with him reaching in the car being a tripwire, if he didn't come out with a gun, it would have been a long road before they were cleared. Quite a few people here would have called them out right murderers, but this time you get to see the other outcome.
The problem with training at that level is you end up with injuries. I've seen blown ACL/MCL, broken arms and legs, and at least one neck fracture I know of. Even UFC fighters don't train hard all the time, they train up for the fight, it's a huge deal to postpone a fight at that level because the training is timed (for lack of a better word) to peak the night of the fight. You simply can't train for this level of conflict constantly and not wear out.
I would love to be in the shape I was at 29, but three kids, 50+ hr work weeks (most of it spent driving in a truck), I just simply don't have the time to work out and post to NES.