I believe that if a wrestler bites his or her opponent, he or she will be disqualified from that tournament. I know that my son has come home with numerous scratches, a black eye from an opponent gauging his eyes,and other marks of competition. I have seen refs give more warnings than points, and I have seen refs look the other way. From year to year, wrestlers change techniques, learn more rules, and get better, with the help of good refs. There are great refs and so-so refs, but they are only human and do the best they can. There is nothing worse then parents feeling their children have been cheated do to an emotional grapple, that only shows the kids that justifyng a loss is ok, but really it is extremely bad sportmanship.
However I do agree with wannawrestle, I would much rather my son lose with a little pride than win as a street fighter. Battle scars for some reason are a trophy for these older kids, and to say that they won on top of the scars is even better.