I would prefer teachers stick to teaching and not comment on specific You Tube videos. You see only a small part usually and only what the person wants you to see.
I read a article about the police in the small city my wife went to high school in. The officer made an arrest and somebody filmed a 5 minute part of it and even thou the officer did nothing wrong on the You Tube video, the arrest became physical when the guy made contact with the officer. The You Tube video made it look like the officer just threw the guy down and people were all over the police brutality angle.
What people did not see is that the whole situation lasted about 30 minutes and the whole thing was caught first on the officer's car camera, then on his body camera, then on his taser camera (drawn but not used), and finally ended with back with his car camera.
If you just had the You Tube video then it would look good or bad depending on your POV. When viewed in its entirety it was a good arrest. Not trying to defend what you can see on the video from Dallas just pointing out that it may not always be as it seems.