Physics

As a disclaimer, I have not watched the video due to being on a phone without headphones. Anyways, here is what I am getting from the thumbnail.

It looks like the argument being presented is that one observer sees light travel along a longer path than the other. The problem with saying this is that both people will measure the speed of light to be the same. This requires time to 'tick' slower in the frame observed to be moving relative to the grave that is stationary. The really fucky part of special relativity is that both observers see the other observer moving slower (general relativity will describe how the two frames reconcile when they stop moving relative to each other).