Kevin R. Kimm (plaintiff) was a highly regarded criminal investigator for the federal Department of the Treasury (Department) (defendant). Department policy limited the employees’ use of government-owned vehicles, sometimes referred to as GOVs. Specifically, the policy permitted an employee to take a passenger in the government vehicle only if the passenger’s presence was essential for the successful performance of the employee’s official business. Kimm was on call at all times and needed his government vehicle to perform his job. In August 1962, Kimm’s wife temporarily suffered a serious medical emergency that prevented her from driving the Kimms’ son to and from daycare. During this emergency, Kimm occasionally transported the son in Kimm’s government vehicle. Kimm believed that the Department generally overlooked this kind of government-vehicle-policy deviation, and that the deviation was essential if Kimm were to remain available for his official duties while responding to a family emergency. Kimm therefore believed the deviation was permissible under the Department’s government-vehicle policy. However, the Department viewed Kimm’s deviation as a policy violation and suspended Kimm. In response, Kimm lodged a complaint with the board having jurisdiction over federal-employee disciplinary actions, the Merit Systems Protection Board. A board administrative judge, sometimes called an AJ, found that Kimm’s testimony about his state of mind in August 1962 was inherently more credible than the Department’s testimony on that issue. Accordingly, the administrative judge ruled that: (1) the record, taken as a whole, did not contain sufficiently substantial evidence to support Kimm’s suspension and (2) that Kimm should be reinstated in his job. The Department petitioned the full board for review. The board reversed the administrative judge’s ruling and upheld Kimm’s suspension. Kimm appealed to the United States Court of Appeals for the Federal Circuit.