Which came first?

Heard about this one on Radio Lab. The episode was about searching for the truth and included an interview with filmmaker Errol Morris. Here's a bit about the photos from Radio Lab's website:

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 Shot.

As Errol explains, it turns out there were actually two photos -- both taken from the same spot over 150 years ago. One image famously shows a road littered with cannonballs (top) while the other shows the same road with no cannonballs (they're off to the side in ditches) (bottom). Which one came first? And why would the cannonballs have been moved?

 You can hear the story here.