The first case is a man that refuses to speak, who turns out to be a monk who has taken a vow of silence. Most monastic vows of silence are limited to certain places and times, and the monk is still permitted to communicate in writing and with special sign language.
When the victim postal clerk begins to speak, excruciatingly slowly, Christine notes that he has a legal right to speak. Only the defendant has a legal right to speak at trial. Other witnesses must be called to testify or be given leave to speak at the court's discretion.