That one’s true. Pleasance was shot down over Germany in August, 1944 and spent the rest of the war in a POW camp. He was something of an adjunct technical advisor on “The Great Escape,” helping make things as accurate as possible.
Now I am racking my brain over who it was that was a POW, some kind of celebrity, and hated Hogan’s Heroes. I could have sworn it was Serling.