The PIC time to which you refer was probably gained at a UAS back in the days when all previous flight time under military training was allowable towards a PPL.
That remains the case for the NPPL; however, with the advent of part-FCL, 22 Gp didn't negotiate any credit towards Part-FCL licences for anyone who hadn't passed EFT. Not even for PIC time in SEP aeroplanes such as the Chipmunk, Bulldog or Grob Tutor. They also completely destroyed the carefully-crafted military accreditation scheme which had worked well for many years under JAR-FCL....
Was this to 'lock in' pilots who were getting so fed up with the RAF that they were leaving in droves for the airlines? Who knows - but if that was the intention, it hasn't worked!
The solution (at the moment) is for the chap to obtain an NPPL, then do the NPPL-to-LAPL-to-PPL conversion. That way he secures credit for some exams and for all his previous flight time; he doesn't actually need to
hold a LAPL but when he meets the NPPL-to-LAPL requirements, he can go on to complete the LAPL-to-PPL conversion.
The CAA have confirmed that this is a perfectly acceptable (to them) workaround until 22Gp can find the time to sort out the mess of their own creation. Don't expect this to happen anytime soon as they claim to be 'too busy with more important matters'......
Such as releasing the 'Future of the UAS Scheme' paper, which is no doubt waiting until after the election. But will there actually
be any future for UAS flying? It's now almost 10 years since the infamous Marston 'report', perhaps the next step will be even worse than that was?