He opposed German Rule over Hungary, not necessarily the Nazi Part.
He was more of an independent opportunist. He made alliances wherever he thought it would help him the most, not on ideological grounds.
He aligned with Germany in WWII but for political gain. He did not oppose the Nazis. He was forced to collaborate with them due to various threats from Hitler's regime, including death threats against his son.
He was a witness at the Nuremburg Trials, but not a defendant.