[Brian Bines]

Brian I think your original question could only be answered if there had ever been any case law on the subject. According to a 'K' report in 1944 when the Germans were preparing a captured P 47 for recon. over the UK the aircraft was to be left in its original camouflage but given German markings to protect the pilot if captured. The KG 200 crews flying B 17's on agent dropping missions had Luftwaffe markings and captured crew were treated as POW's, but as already stated it is likely Graf Spee's Arado crew should not have attacked while in Allied markings. I suppose if an aircraft was operated in enemy markings there would be the question of who broke the rules of war the crew, or whoever ordered them to fly the mission. If the ruse was discovered would the crew have the right to defend themselves while in the markings of their enemy ?
The other point is that the rules of war are applied by the victor. For example I believe the German commandos who wore American uniform in the Battle of the Bulge were told providing they did not fire when in US uniform they would be treated as POW's if captured. This view was not shared by the US Army who shot many of those captured despite no opposition being offered at the time they were taken prisoner. In the book ' Commando Extraordinary ' it shows Skorzeny was put on trial for war crimes but the case was dropped when W/C Yeo-Thomas gave evidence that some British Secret Service operations were carried out in German uniform.
Altogether one for a legal expert to answer I think,

Regards
Brian Bines