Antоniа is а lаwyer with twin sоns that are 12 years оld. Antonia is resting in her bedroom when she hears loud noises in the family room. She springs up, runs to the family room, and sees one son, Leonidas, punch the other son, Charles. Antonia immediately orders Leonidas to stay in his room for the rest of the day and to not use the internet for 48 hours. As Leonidas mopes along the hallway to his room, Leonidas shouts, “Charles punched me first!” What legal principle would Antonia recognize Leonidas’s remark as being?