Washington Cleaning has more than 50 employees and has several contracts to clean offices in the central business district. In order to keep disruption to a minimum, the teams of cleaners do not commence work until after 6 pm each night. In the working papers documenting the control testing results the senior auditor notices that there was one instance of a part-time staff member for Washington Cleaning being paid an incorrect hourly rate.

Required

Explain why the result shows a control exception (deviation).