Beagle,
Of the hundreds if not thousands of such events against Allied Airmen...you pick one about an American Pilot shooting a German?
Might I remind you of how the game was played during WWII....it was no where as dignified as you wish to think.
Shall we remind you of the "Commando Order", the Murder of RAF Officers during the Great Escape, and all the other Atrocities committed by German Forces against Allied Airmen and Soldiers? Ever read up on the atrocities committed against Allied Bomber Crews after they parachuted from damaged and downed aircraft?
Get your head out of your Butt....you can call such actions War Crimes....but in the scheme of things....it amounts to nothing.
The Germans and Japanese were murdering Tens of Millions of Human Beings....and you get some begotten notion about the Chivalry between Airmen?
Do spare me will you....War is about killing the enemy forces personnel and rendering as many as possible Combat Ineffective. Killing them dead accomplishes that.