West Coast,
Could that be because Col Olds was a member of the USAF and, therefore, required to adhere to the regulations contained within AFI36-2903?
A member of the RAF, on the other hand, would be required to adhere to the regulations contained within the Queen's Regulations for the Royal Air Force. Could an order, even from a General, to contravene QRs could be classed as an illegal order?
Perhaps there is a reference to exchange personnel being required to adhere to regulations of the foreign service with regard to uniform, facial hair, etc that I have missed?