If the UK Military allowed pilots who have reached the equivalent civil goals to have a civil licence (as some countries do), then he wouldn't have to do it.
Why not ask? If you don't ask you don't get. You at least know where you stand then.
When I left the UK Military I had an ATPL/H (paid for by me)gained using exam exemptions gained from the aircraft type I flew for technical and also Nav subjects. The CAA at the time agreed that military training in most subjects was of equal standard to that for CAA licences. I did have to do the Loading and Air Law exams, both of which were not covered to the extent that civil pilots were expected to know for the former, and that UK military Air Law was slightly different to that of UK Civil.
That has now changed because the UK military didn't like all those qualified pilots it trained disappearing to civil jobs, so they tried to keep them by removing the exemptions. It didn't work because those that wanted to leave paid for their exams and tests.
However, many, like me, didn't have an IR. Most companies paid for and sponsored us for IR courses. OK, so we were bonded, it was still sponsored and we were paid for it. What's the difference?
This almost sounds like an anti-military stance again that was on another topic a few weeks back.