I think he dropped it behind the fence when he had his back to the cop but then he turned around quick and that was it.
He was carrying a gun in his right hand, not clear when he dropped it, must have been immediately before he was shot.
Could be. I've seen the pic of the recovered pistol, a 9mm Ruger, and understand he had gunshot residue on his hands. In the video it looked like there was an object by his right foot, but behind the fence would make more sense for a drop. Also worth remembering they were responding to shots fired.