I have no idea if the claims in this book are true or not, but the previous story was that Coco Chanel was a “hero of the Resistance”. So many Frenchmen always claimed to be in the resistance that I always find that claim suspicious.
If you listen to the French, everyone was in the resistance :-) In reality, French industry made weapons for the Nazis and was paid for it. French eagerly reported their Jewish neighbors. The story of Marcel Bloch (a.k.a. Dassault) is the most telling.