Binegar (defendant) worked in the Medical Logistics Office (MLO) at Hanscom Air Force Base. Ordering contact lenses for service members was one of Binegar’s duties. Service members who required contact lenses to perform their duties or correct medical conditions were entitled to receive them free of charge through the MLO if they presented both a prescription and a purchase letter from the optometry clinic. Both the optometry clinic and the MLO failed to follow the applicable processes for confirming the appropriate purchase of contact lenses at the government’s expense. At multiple points in his tenure at the MLO, Binegar was provided with incorrect information from his superiors regarding entitlement to contact lenses through the MLO. As a result, Binegar was placing inappropriate purchase orders. Supervisors failed to sufficiently review Binegar’s purchase records to confirm that purchases were being billed to the correct accounts, and Binegar was never informed that he was performing his job incorrectly. Binegar was found guilty of stealing contact lenses and conspiring to steal contact lenses under the Uniform Code of Military Justice (UCMJ), 10 U.S.C. §§ 801–946. The military judge instructed that mistake of fact was only a defense if Binegar’s mistake as to the ordering requirements was both honest and reasonable. The court of criminal appeals agreed, and Binegar further appealed on the ground that his mistake needed only to be honest to support a mistake-of-fact defense.