Your top photo looks to me like the bikers fell on the ground to avoid the shooting. (Piled on top of each other, trying to get behind/under the cars.) And then the cop yelling to “spread em” - or perhaps that was more by instinct by the bikers. (That’s what I’d do!)
The cop is facing downrange and exposed. Many of the bikers are looking in the direction the cop is looking. I’m guessing that was the direction all the action was at the time.