There are many forms of "gamesmanship", some involve actual pain and as an experienced judoka (I like to think so at least) I accept that "accidents" will happen.
Biting however is low, in any sport or activity. There is no room for it ,and any person who bites someone in the pursuit of any sporting activity should be banned for life.
Mike Tyson and Luis Suarez are two examples of piss poor excuses for human beings, who made millions while engaging in such practises.
Suarez has been caught twice and yet he still plays in the English premier league, WTF????