It continues because his coach allows it.
I have had a few players in my coaching tenure with this kind of tendency. Benching was usually the first step, because they want to be competing and playing more than anything. If they are just your average once-in-a-while douchebag, it usually worked. The threat of not playing was enough to curb their impulses.
Davison has likely been like this his entire career, with a plethora of excuses made by everybody and anybody that saw it happening. It paid off for him, so the reward circuit was hard-wired in his brain. This prick knows exactly what he is doing, as do his coaches. Referees should also be well aware of his antics, and take that into consideration when officiating a game. Either these guys didn't know, or they don't care, but all it does is reinforce that this kind of play is acceptable.
Let him try something with somebody like Cockburn. Then you'll see him scampering for safety before the guy rips him in half. If I were the official, I'd tell Cockburn he has 10 seconds of no-peeking before I blow the whistle.