Sedatives cannot work that fast. My expertise is on the cervical spine and brain stem. It appears that the one officer in the back right very well could of had a small knife and stabbed her through her C1. Your body would instantly go limp. You don't have to cut the spinal cord completely to get that reaction. The nervous system could still operate some of your basic systems. This is the cheapest way to get rid of someone.
BTW….has anyone seen any of our Hong Kong protesters? Could these be the roundups? Me thinks so. Just a thought.