Nah, seems legit for sure. The only thing that would lead anyone to doubt that would be the last shot Moorer lands, which wasn't much more than a cuff to send him down. The one before that was a sharp hook flush around the ear/temple. Getting hit there will completely mangle your equilibrium and could easily take a second or two to have full effect, which it seems happened here. Couser was obviously still concious and writhing around so that looks weird, but anyone saying it was fake probably couldn't imagine what his head felt like at the time.