Does anyone know what the facts were? Did Wolf own the painting? If so, where did it go when he went to South Africa? On the face of the description, looks like Ms. Taylor may well have acquired real legal title.
IMO the Mautners owned it in 1939, it "disappeared", as though there's any question what happened in 1939 Berlin, but there's apparently no document establishing Nazi confiscation, it reappeared in 1963.
Berlin to South Africa to Canada, I can believe the heirs didn't know about this specific painting, and the courts decision is it's decision.
My impression it that the stumbling block to an agreement here was Liz, who was uncompromising in the face of the paintings obvious background.