Maybe not a Glock, but it's quite likely. He might have pre-cocked a DA first shot pistol, and then under stress he put some weight on the trigger, as if it was still going to require a DA pull.
This used to happen with revolvers a lot. Riots in Miami broke out in the mid 80s when an Hispanic cop had a black kid spread over a pinball machine, prior to cuffing him. The cop cocked his DA revolver, and when the kid allegedly moved: "BANG!" A lot of police depts removed the SA sear from their revolvers after than, making them true "DA only" guns.
Now, with 50 different auto pistols in use, it's a real bag of worms. Cops may be using SA only (1911 type), DA only, DA first shot followed by SA follow ups, Glock "safe action" which is close to SA, and so on.
If cops are transitioning from one type of pistol to another with a different trigger type, you can have real problems. When that "muscle memory" kicks in, and under great stress your reptile brain think it's going to take 12 pounds to make that BANG and it takes only 4......
This is not "thought out," that's the point. It happens on an almost unconscious level. This is why much training and uniform policies are super important.
In my civilian peace officer days we were trained to cover at low ready index finger on the slide. That way if a negligent discharge occurred less likely that someone would be killed. Also not at play in this incident but has been an issue in other wild fire shoots by police, not everyone had sidearm out. If you had 2 officers one covered while the other cuffed. I have seen a lot of "circle" shootouts lately with 5 and 6 officers blasting away at one suspect. We also had to qualify every 6 months with what we carried. I will look at the vid again and try to go frame by frame to see what type of pistol it is but CA agencies seem to love glock and a lot of those departments are set up to where you carry what your are issiued
100 + MPH Chase ?.......:o)
Rarestia's comments mirror my own opinion. I use the seatbelt, and the cruise control and avoid the rolling stops to prevent "any" contact with a LEO who may be the finest human beings with a badge on the face of this earth or one lousy loser piece of sh*t that considers themselves above the law and operates outside the law.......
This SP didn't deserve to be shot for standing up per the video observed. Even if he was not ordered to stand up or was told to stay down......
One key problem with LEO's per my experience and firsthand observations is that when a LEO breaks the law and gets fired they, in most cases, get to keep their certification but lose their commission at their former department and are free to seek employment with another department in that state or even another that will accept the certification .
LEO's fired with due process or prosecuted , that consider themselves above the law and operate outside the law, need to be unemployed and banned in any occupation that deals with law enforcement.
Ya'll Stay safe !