I don’t know about that, but the story of the Borie and the Card Task Group will get extensive coverage in the N.Y. Times when the story comes out.
I found no reviews commenting on Raynor's inspiration for the book. He wrote fairly extensively about his experiences after the war, both fiction and non-fiction. That said, he almost certainly would have been aware of the Borie incident, so I suppose it's possible he used it as a vehicle for the story he wanted to tell.
It’s just unbelievable to me that Hitler is allowing another army to be cut off. It’s much smaller than Stalingrad, but sheesh that man learns nothing. Reminds me of what was said of the Bourbons, they had learned nothing and forgotten nothing.