A really used camera

A reader sent me this picture – the film shape actually got imprinted in the camera’s back (Leica M4). Sorry, I cannot post the original picture here. The camera belonged to Garry Winogrand. Is this even possible? I was looking at another beat-up Leica M3 on eBay and the back plate was unmarked, see below (btw, did you see the eBay price?).

More images available on eBay