Subject: Ruling when ball hits the ceiling

This happens quite often in USTA indoor matches.  We all know if the ball we hit "obviously" hits the ceiling the point goes to the opponent.  However in two recent indoor matches...one team felt they hit the perfect lob....their opponents disagreed. and claimed it "grazed" the ceiling. Neither team could agree.

Who makes this decision or what is the "official" ruling. .I feel this should be addressed in "The Rules" or "Friend of the Court" so that it can be looked up when needed.    

CleoKAUFMAN: When the ball is hit legally by your opponents and is headed your way, and then the ball touches the ceiling, you would make that call against your opponents.

The Code #20 and #21, Friend At Court (page 47-48)