Sorry -- hit the wrong key (don't even know which one).

23 Aug 39: Hitler-Stalin pact
01 Sep 39: Britain enters war
24 Jul 40: E.M. conscripted
18 Dec 40: E.M. declared a deserter
22 Jun 41: Germany invades USSR
08 May 45: War in Europe ends
16 Dec 46: E.M. arrested
ca 11 Feb 47: Court martial canceled on medical grounds
26 Feb 47: Moved to hospital
10 Apr 47: Released

He deserted, then, while the war was still an imperialist war according to the USSR, and then found himself in a permanently embarrassing situation when it suddenly became a war against fascism. Such things happen. My main wonderment is why the authorities treated him so gently. I could make up an amusing story, but so could you.