Errol Morris is a legendary fact-hunting documentary sleuth. His film The Thin Blue Line has been credited with overturning a murder conviction, and freeing an accused man from a death sentence. For him, the search for truth shouldn’t stop short of insanity. He tells Jad and Robert a story about his obsession with one particular photograph. Taken in 1855 during the Crimean War, the photo – titled “The Valley of the Shadow of Death” by its photographer, Roger Fenton – is one of the first photos ever taken of war. And it may also hold the title of First Faked …