From what I understand, the water bottle was a mace canister. Some reports were saying the guy was reaching for it to use as a weapon but I don’t see that. It is then kicked away. Also, pay attention to the agent in the gray jacket. He walks up a bit late, and disarms the victim by pulling the (holstered) pistol from his waistband. He then runs away holding the weapon as the victim is shot. Like a dozen times.