In the teachers defense, the boy allegedly threw a ruler at him first. If it goes to court, he plans to plead that two wrongs do in fact make a right. I am sure there are proper way to restrain unruly children, but if I were to wager a bet, I don't think that pinning them against a table and waiting until they cry 'mercy' is one of them. Please let me know if I am off the mark.
