The hold is a carotid artery move and when applied is very effective. The problem is you learn it in the academy on a passive subject, applying it to a 350 struggling suspect is an entirely different scenario and adds many dynamics (good an bad).
Right you are. I had a fireman apply it to me during a demonstration of how firemen remove uncooperative people from burning buildings. I instantly collapsed, like a sack of potatoes.
The question here is to whether or not the cop over-applied the maneuver. IMHO that's a question to be decided by a petit jury in an open court.