Was not Rommel in May 1940 in overall command of an armoured force including Waffen-SS units that shot British POWs?Let's start with the war crime Rommel is supposed to have committed. What is it?
If one wanted to be hyper-legalistic, one could hold Rommel responsible for criminal actions committed by troops under his command, even though he had certainly not ordered them. If he had not prevented them or subsequently punished the perpetrators, that might be sufficient cause to hold him ultimately responsible (if one wanted to be bloody-minded).