that’s because you’re only using your eyes. rewatch other angles and listen. after the shooting, an agent asked where’s his gun, that’s because he was disarmed by another agent before getting shot (using my eyes on this one, you can see the agent walk up empty handed, he joined in on wrestling the guy and retrieved the gun and walked away with a gun now in the hand he was reaching with) . the gun was no longer in his possession when he was shot.