A oppostion player calls injury during the motion of throwing. This affects the throw as the thrower tries at the last minute to stop throwing. This results in a turnover upfield, far away form the injured player.
Does the disc go back to the thrower or does the play stand? What would have happened if the throw was completed?
Play stops when the injury occurs (unless the injured player chose to continue playing).
If the thrower still had possession when the injury occurred, then any subsequent pass will not count, regardless of it being completed or not.