I wonder if he went so far off in the divergence if a different reality not simply historically but, physically could have happened. Maybe if he went far enough out there would be magic or something like that in another line.
Another outstanding insight. Is it possible to travel to a world line that is so different that the known physical laws no longer hold sway? What would happen to our time traveler friend in such an event?
I would think it would be a one way ticket then once you enter your stuck? Or maybe you would be stuck in some type of void in the process of trying to enter the world?