I think it's a ridiculous idea. Yurovsky would never have allowed any of his men - or Ermakov's - to take photographs, much less film the executions, even if it had been possible (which it wasn't, given the technological and time constraints). Yurovsky was a thorough-going, conscientious revolutionary and Bolshevik - very ascetic, methodical, and deliberate. None of that bully-boy, Nazi posturing over the victim for him. It was all business.