Mr. Kirk needed to have his knee replaced. Dr. Spock performed the surgery, but left a sponge inside Kirk's knee resulting in a severe infection. Kirk suffered tremendous pain and suffering and had to undergo another surgery to remove the sponge. Dr. Spock had exclusive control over his medical instruments and other materials, including the sponges; the harm that Kirk suffered does not normally occur without negligence; and Kirk was in no way responsible for the harm as he was asleep under general anesthesia. What would Kirk's best legal theory be in bringing a lawsuit against Dr. Spock? _________________