Greif Brothers Corp., a steel drum manufacturer, owned and operated a manufacturing plant in Youngstown, Ohio. In 1987, Lowell Wilson, the plant superintendent, hired Youngstown Security Patrol, Inc. (YSP), a security company, to guard Greif property and “deter thieves and vandals.” Some YSP security guards, as Wilson knew, carried firearms. Eric Bator, a YSP security guard, was not certified as an armed guard but nevertheless took his gun, in a briefcase, to work. While working at the Greif plant on August 12, 1991, Bator fired his gun at Derrell Pusey, in the belief that Pusey was an intruder. The bullet struck and killed Pusey. Pusey’s mother filed a suit in an Ohio state court against Greif and others, alleging, in part, that her son’s death was the result of YSP’s negligence, for which Greif was responsible. Greif filed a motion for a directed verdict. What is the plaintiff’s best argument that Greif is responsible for YSP’s actions? What is Greif’s best defense? Explain.