Officer chases an SUV, which crashes and the two criminal POS's jump out, one has a gun. The officer begins to move with them or at them, he see's the gun, draw's, or tries to, he tugs on his gun once or twice and presented. Now he's right handed, the two guys are on his left side. He slows down and begins to fire. Cannot really tell the rest. Sort of looks like he starts to backup and/or completely stop.
First observation being obvious, if you are not familiar with your equipment you will not rise to the occasion. The video, though very quickly, shows at least a single tug (though it may look like two) to which looks like a duty-grade retention holster. Dry fire practice, dry draw practice will help. If you carry a gun in a holster then you should do yourself the service of training with it.
The other aspect to consider here is drawing your pistol, when you are moving and/or running, especially when you are taking fire. Practicing for this specific type of situation is important enough that you should do so whenever you have the ability. Even dry, moving quickly, drawing and shooting is still better to do before the day you actually have to do it for real.
When you move, draw then shoot, or draw, move then shoot, or draw, shoot and then move, which is more important? How fast should you be moving? Might be worth doing on your own or at a range.