The point is that it changed in ways different to his twin's body, and some of those changes even reverted once he was back on earth for a while. It's pretty un

The point is that it changed in ways different to his twin's body, and some of those changes even reverted once he was back on earth for a while. It's pretty unlikely that this is all just an anomaly and the regular changes of a body over the course of a year independent of the fact he was in space.