Social Psychology / Dichotomy Explanations

Two men were arrested for assaulting each other in what would be called a "bar brawl."  The bar owner did not press charges, and the two men were released. The next week, people gathered in the same bar to watch "pay-per-view television." The same two men got into a cage and behaved in exactly the same manner. Neither of the men in the cage was arrested. Both, in fact, were paid handsomely. How can this dichotomy be explained?