Standto,
Not sure why you criticise the RAF for letting John Marden get back to flying a Jag. He was an outstanding guy, and an outstanding pilot - I speak from personal experience as I shared two tours with him on each of Jaguar and Hawk.
You can't keep a good guy on the ground and his heart-lung transplant had been fully successful. The latter didn't take away his pilot skill, indeed, it gave him the physical strength and stamina to enable him to practice it. So full marks to the RAF for letting him continue to practice his art. He was also a good instructor, so had he continued he would have passed on his skills to the next generation, which is a good investment for the RAF, n'est ce pas?
Just prior to his death he was planning a charity flight in a light aircraft from John O'Groats (sp??) to Lands End. He told me about it during a conversation when he also challenged me to a game of squash. Unfortunately, neither came to fruition.
I missed him, and I still do - he was a great loss to the team.
A