The original post is not about distance, but about the changing directions of the photons. The answer is that we can get confirmation by looking at such objects as the Einstein's Cross the scale of the deviation from true direction that object night have. We can also tell similar things from the weak lensing surveys we use to locate dark matter in Galaxy clusters. The answer is that in most cases, the variation in direction of the photon doesn't change more than an arc-second or two over a 12 billion LY flight.
Originally Posted by 0Tun0
Forming opinions as we speak