Because photo's "don't move", if they did we would call them a video.
The link below is to a video which shows movement. And it is the one I took the screen grab from. It cleary shows from two perspectives that Pretti was disarmed, that Officer Gray Coat exited the scrum and that the shot in the back occured AFTER he'd left the scrum.
Now think through this.
The video's do not show a discharge. The officer (I'll call him Officer Gray for his coat) that recovered the firearm left the scrum with the firearm in his right hand.
Human nature and especially for law enforcement, instinct is going to be to look in the direction of a firearm being discharged to assess the situation and any possible threat.
Now watch the videos, at the time the first shot is fired, Officer Gray looked over his shoulder to his LEFT because that appears to be where the sound comes from. He was holding Pretti's firearm in his right hand, if that gun had accidently discharged he wouldn't have looked left, he would have looked right at the weapon in his hand that had just fired.
The "accidental discharge" theory make no sense. As a matter of fact video analysis shows that the officer in the blank mask behind Pretti that had just watched Officer Gray exit the scrum was the first to fire based on sound, pointing the weapon, and his arm recoiling do to his discharge.
Now if a ballistic report shows the gun was discharged and compares a recovered shell casing against gun markings? Sure, I'll agree there was a discharge of Pretti's firearm.
WW
.
.
.