From what I've read the rule on this differs in different countries and regions of the World. What exactly is a rabbit punch? I always thought it was punching directly to the back of the head when in a clinch but some say its illegal even when a fighter is ducking and tilting his head so a fighter cannot avoid hitting the back of his head. Also is it illegal to punch behind the ears?
Technically it is illegal to hit behind the ears but difficult for officials to enforce. Shane did this a lot in his career.
Its illegal to hit behind the head in any situation. Its a question of protecting fighters. Even if the fighter has his back to you, you can't hit him behind the head. its also illegal to bend your head below your opponents belt, but that infraction is alot more tolerated because you don't put your opponent's health at risk. http://www.ringsidebygus.com/boxing-fouls.html
A lot of times fighters are not to blame esp. when their opponents constantly are moving there heads in ways that could lead to a rabbit punch. A lot of acting and complaining has led refs to target an opponent more than the other. It breaks up any fighters confidence and rhythm as in the case of Quintana/Berto fight. Hopkins/Jones fight is another example. Fighters have to quit the crying and using this tactic, which is very shameful.
Well it depends...if someone is fighting Berto then anything other than a straight shot is illegal. I hope this rule spreads, hooks have been ruining the sport for decades.