Yeh, I got my terms confused. My bad. Disparity is, I believe, only possible to get from a stereo pair. TFA presents something closer to a camera track, albeit a very short one. From a camera track it is a short hop to extracting a point cloud. What make the author's approach possibly unique is that the foreground object is in motion as well as the camera. In standard VFX foreground object motion is usually avoided.