I'm inclined to let Spielberg slide on the snake reflection only because he has insisted it's only really visible theatrically on a "bad print", aka one that isn't dark enough or whatever. They're already doing all kinds of electronic tinkering just to get a celluloid movie translated to a video disc, so, hey, what the hell. If he signs off on the CGI cliff for the blu-ray, that would be a different thing. It is getting into a weird area though, I know Superman III has visible wires that you would never have seen in the theater, there really is no good way to hide that without going digital.