Most possibly, however, that´s all we got for now. It could be simply that light speed is not faster than instantaneous, and for that matter, space, time and speed behave at those greta magnitudes in a way more like our scale of time. I´m not a genius, but it would make more sense for me.
If you cross a lightyear in half a year and "jumping" out of FTL half a year after you did so? why not? Let´s say, that for travelling backwards in time, you need to move from A to B faster than instantly, theorically fast enough to be at both places at the same "time". If that´s a LY, and you spend half a year on the way you are not in both places at the same time. I know there is a lot of theory and observations that support einstein theory, but why coulnd´t it be that simple? maybe time is more coherent within space than he thought.