The trouble with human bites is that medically they are worse than a dog bite for infection risk if the skin is broken.
The video clearly shows a voluntary additional neck extension and biting action, not merely a passive bumping of teeth and shoulder.
Then, realising the foolishness of his actions, after a split but distinct second, he feigns tooth pain...
The chap's a psychopath. God only knows what his poor wife has to suffer behind closed doors.