Why is Kumalo upset that John Kumalo decides to get a lawyer to defend his own son in the trial about the murder?

Kumalo is upset about John Kumalo hiring a lawyer because he intends to have the lawyer lie about his own son’s presence at the time of the murder. John Kumalo is willing to scapegoat his nephew to save his own son, rather than rallying around the family, or forcing his own son to accept responsibility for his actions.