Adolf Heusinger was a German career military man since 1915 - well before the Nazis came to power, and considering Germany went through multiple power transfers in his time I kind of believe he was under the impression it was just yet another regime taking control and carried on with his business. He was later put on trial as an accomplice to a plot to assassinate Hitler and served West Germany before joining NATO's Military Committee for 3 years. He wasn't their Chief of Staff, that's for certain.

I'm not into defending Nazis but there is so much more nuance than this meme is depicting.