Another angle, I would not equate this to a NVA emblem on a US vet's cap, there are areas in France that are also German, while visiting a distant relative in Strassbourg France, I was interested to see a photo of their grand father in a German uniform of WWI, next to their father wearing a French uniform of 1939. Also, acording to Henri Barbuse's book "Le Feu" there was not always a hatred between the common soldiers of opposing sides, at one point in the book he tells of German and French soldiers banding together and helping each other as they try to seek shelter from artillery bombardment.
Gus