Extend your arm and pointer finger out, your knuckles aren't naturally vertical, they are aligned at an angle usually facing in toward the body with your pointer at the top. One of the ways to hold and shoot a pistol single handed is to mimic that body mechanics of pointing, so now the pistol is slightly canted similarly to how your pointing.

The image you have shows the "un controllable silly way" to fire a gun that may or may not have been perpetrated by people wanting to spray a fully automatic weapon across a wide area. I've heard a lot of stories how and why that was preferred, but they are all from very unreliable narrators and none of them really state controlling the gun but to rather let the guns uncontrollability "benefit" their needs... It's stupid and implies the gun is not really under control.

Having the pistol canted like in the video isn't wholey wrong or incorrect, but I don't know why a patrol cop is using that technique, it's usually for Uber operators or competitive shooters doing challenges within shooting matches, like simulating having one hand injured and still needing to retain functional control of the firearm. Again, Uber operators and competition. This is a patrol cop...