Catherine Wagon seller was a nurse at Scottsdale Memorial Hospital and an employee at will. While on a camping trip with other nurses, Wagon seller refused to join in a parody of the song, "Moon River," which concluded with members of the group "mooning" the audience. Her supervisor seemed upset by her refusal. Prior to the trip, Wagon seller had received consistently favorable performance evaluations. Six months after the outing, Wagon seller was fired. She contends it was because she had not mooned. Should the hospital be able to fire Wagon seller for this reason?