Erwin Rommel was a very hard-bitten guy and by all accounts a brilliant general. (According to one military historian I’ve read, Rommel was the only true military genius to emerge from WWII.) By being a good soldier, he served the Reich, but from what I’ve read his service to the Reich was nonetheless relatively “clean” – i.e., not directly involved with Nazi war crimes per se. I don’t know what his personal opinion of the Einsatzgruppen units was, or if he banned them from operating in his theatre (as did General Von Paulus did at Stalingrad).
Rommel’s frustration mounted throughout the war, since his vision of the potential of the Mediterranean/North African campaign was at odds with that of the many brownnosers in the Army General Staff. Some historians have argued that if Hitler had allowed his more perceptive generals (like Rommel) to pursue a more aggressive and more astutely run campaign in the Mediterranean and North Africa – e.g., taking Malta instead of Sardinia, and better supplying Rommel before Patton could help to shore up the Allied presence in North Africa – then Germany conceivably could have run the Brits out of Egypt and disrupted Allied supply and transport lines through the Suez Canal/Red Sea shortcut (while forcing the Brits to reorganize defensively to protect India), prevented the Allies from shoring up the North African theatre, and eventually could have pressed on through Iran to secure crucial oil fields, while cutting off Allied supply lines to the U.S.S.R. Rommel understood better than only a very few others the true potential of such a campaign, had it been pressed aggressively and early ('40-'41); incredibly enough, Hitler never did.
In addition, Rommel was repeatedly denied the men, tanks, materiel and fuel he needed to achieve the limited military objectives that had been approved for him. It has been argued, for instance, that had Rommel been given just one more tank battalion at the right moment (when he was screaming for just that), he could have driven the British out of North Africa.
While Rommel’s early victories had brought him great favor with Hitler early in the war, but his [impolitic] outspokenness [and rage?] and determination to argue for his favored war strategy undermined him politically with Hitler and the insiders in Berlin. His early invincibility may have also worked against his interests by encouraging the war planners to take his abilities for granted, to push his capabilities to the max, and to not supply him with quite enough of the men, materiel, etc. that he needed.
Rommel had become involved with a group of military officers who were making discrete inquiries (with the Brits, I think) into the possibility of striking a separate peace. [I don’t remember when this was supposed to have taken place; summer/fall '44? Or as early as '43?] Some believe that Rommel had also become involved in a rather vague plot to assassinate Hitler, but I believe that most historians reject that view.
When Hitler learned (or at least became convinced of Rommel’s involvement in) the separate peace scheming, he presented Rommel with a dire choice: to either subject himself and his wife and their only son to the judgement of a Nazi “People’s Court,” (a kangaroo court that would very likely return guilty verdicts, and capital punishment, for all three), or to take the gentleman officer’s way out, through suicide, which he was promised would protect his family.
Rommel took the poison offered him and died in his jail cell. His family was protected, as promised.