AE v CFM
Prangster.
I think you might be muddling up the medals. Your mate did not get the AE for being CO of an ATC Sqn for 12 years. If the medal is the AE, he got it for 10 years in the Reserves - either RAFVR or RAuxAF - (less if it was wartime, although I believe only the AuxAF then qualified). If it is the CFM, that is for being an RAFVR(T) officer in the ATC. If he has both and a DFC, good on him - he has certainly put the service in.
It was called the Air Efficiency medal because you had to have received a Certificate of Efficiency for 10 out of 12 years to qualify (and get your bounty). The Certificate of Efficiency still exists for all reservists to qualify for their training bounty.