Touching the official is the same as touching the floor where the official is standing. In
(a), the ball is awarded to B for a throw-in. In
(b), the ball has been in the frontcourt and then has gone to the backcourt while in Team A’s control. It is a violation for A1 to cause the ball to go from A’s backcourt to frontcourt and return to backcourt untouched if A1 or a teammate is first to touch it after it has returned to backcourt.