ancient & thud
There have been many such rulings, but in my own experience the first was by Director General Support Management (an AVM) in December 1992. He threatened those who refused to make false record with dismissal. An Internal Audit report was sent to PUS (Sir Richard Mottram) on 26 June 1996 supporting those who had 'offended', but he didn't act.
The RN likewise on 2 October 1999; but it only regarded it as insubordination, issuing formal written warnings. (Not all the RN - a Senior Captain and Commodore). That was an interesting case, as a Rear Admiral in OR stepped in and supported civilian 'offenders' against the Capt and Cdre. Written became verbal, but the offence itself was confirmed. Who can shoot down a Rear Admiral?..........
The Chief of Defence Procurement placed it in writing on 19 November and 13 December 2001. On 18 September 2002, after unsuccessful appeals, our Trades Union wrote to members advising them of the ruling. (I can't say how widely this was circulated, but I have my copy).
On 23 April 2003, the head of Personnel advised the Asst Under-Secy of State to uphold the rulings, which he did to an MP.
More recently, on 28 October 2014 the Cabinet Secy, the late Sir Jeremy Heywood, formally declined a request that he rescind the ruling. His reply was copied to a Minister through whom the request had been made.
You'll perhaps appreciate I have copies of all this correspondence, courtesy of DE&S Secretariat who were quite happy to provide it under FoI. To read about the inevitable outcome, go to the old Nimrod, C-130, Chinook, Tornado, Sea King threads. Well over 60 deaths.
I should add that on 6 February 2010 Sir Gerald Howarth, former Defence Minister, agreed with you both. It was illegal, and he would have expected his staff to disobey. I was there, in his house, with another ppruner - a retired Sqn Ldr.