Richard Leary and his wife had two sons, approximately nine and 13 years old, when they divorced. The court designated an attorney, Ms. Coates, to act as guardian ad litem, representing the interests of the boys in the custody proceeding. The court did not define the role of Ms. Coates, such as by stating her obligations or the purpose of her appointment. Coates ultimately determined joint custody to be appropriate even though the boys apparently desired to live with their mother. Notwithstanding Coates’s conclusion, the court awarded sole legal custody to Mrs. Leary. Mr. Leary appealed, arguing that the judge erred by not instructing Coates as to her role.