Player A1 takes a throw in from the spot designated by the Referee/AR. A foul throw in is observed by the referee but the ball did not enter the field of play, that is, the ball did not break the plane of the touchline.
The throw in was not executed properly and the opponents (team B) argued they should be entitled to the throw in. But the ball never entered the field of play so the side originally entitled to the throw in (team A) argued they should still be entitled to the throw in because the ball did not enter the field.
What is the proper restart?
USSF answer (July 14, 2009):
The other team was correct; they get the throw-in.
This from the Interpretations of the Laws of the Game and Guide to Referees (2009/2010):
If the ball touches the ground before entering the field of play, the throw-in is retaken by the same team from the same position provided that it was taken in line with the correct procedure. If the throw-in is not taken in line with the correct procedure, it is retaken by the opposing team.