How does McMurphy get back at the black boys during the basketball game?

In Chapter 24, the aides, assisted by two black boys, beat by a margin of twenty points the team that McMurphy and the other men get together on the ward. McMurphy's team, composed of Harding, Billy Bibbit, Scanlon, Fredrickson, Martini, and McMurphy, is slow and short. Chief says, "But something happened that let most of us come away feeling there’d been a kind of victory, anyhow." When a black guy named Washington is trying to get the ball, someone hits him with an elbow. Blood pours out of his nose and chest like "paint splashed on a blackboard," and his teammates have to hold him back as he yells at McMurphy. McMurphy's response is just to sit on the ball and pay no attention to Washington. Though the team made up of men on the ward loses, they have a kind of psychological victory by even having a team and by watching Washington bleed so profusely.