I think he was, he looks very Jewish and was in cahoots with the Jewess Rosa Luxemborg. Almost 50% of the communist leadership in Weimar Germany was Jewish. Its highly likely that he's one of them. He's the one that lost Germany for the communists.

Luxemborg actually cautioned against an uprising but Karl foolish began an insurgency in Berlin. The Prussian aristocracy still controlled the German army and they in conjunction with the Social Democrat chancellor organized the Friekorps and crushed them.

They beat this asshole within an inch of his life before putting a bullet in his head and dumping in a ditch.