Shine a laser into a distant galaxy; interpose a vampire. When does the vampire lose energy? If at once, you have a predictor for whether or not the R-photons are going to hit an object in a few million years' time; if the energy loss only occurs when the R-photon strikes something, or maybe even subsequently when the information about the strike has been returned to the vampire by some kind of "R-antiphoton"… what happens if someone stabs the vampire with a stake in the intervening aeons?

Well, then you have an R-antiphoton containing negative energy which is going to end up hitting something at random and causing an unexpected phenomenon.

If you don't like that, I think the ball is in your court to propose an alternative optical model of vampirism which has fewer problems with conservation of energy :-)

I think it's high time we stopped faffing about with the theoretical physicists and started taking some measurements off an actual vampire in the optics lab.