Good morning all

I wonder if any one can help? I am researching the career of Don Finlay for a forthcoming book but have come across an anomaly. His DFC citation quotes him shooting down a Bf109 on 3 March 42 while flying with 485 Sqn - he was the 11 Gp engineering officer at the time and was flying as a ‘guest’. The Sqn ORB quotes no kills at all that day, in fact it says that everyone came home empty handed. Finlay was certainly flying, but where has this kill come from? Any help greatly appreciated.