"Chewer." The state in which Susan lives has a statute prohibiting dogs running at large. All dogs are required to be on a leash whenever they are off the owner's premises. Susan's dog, while not on a leash, visits the home of a neighbor down the street. While there, the dog carries off an expensive pair of shoes belonging to Robert. The shoes are chewed and destroyed. A neighbor informed Robert of what had happened. Robert commented that he never should have left his $300 shoes lying on the deck in the first place but that he expects to be repaid by Susan. Robert found out that the dog had carried away a number of shoes and other articles in the neighborhood, chewing them to pieces. Susan did nothing to warn anyone. Robert thinks that she should be punished for her activities, which would perhaps deter her from allowing the dog to run loose. Which theory will Susan likely use to defend herself?