this is from the bca rules of pocket billiards
in short
its a foul
......
1.16.1 CUE BALL FOULS ONLY
When a referee is presiding over a match, it is a foul for a player to touch any ball (cue ball or object ball)
with the cue, clothing, body, mechanical bridge or chalk, before, during or after a shot. However, when a
referee is not presiding over a game, it is not a foul to accidentally touch stationary balls located between
the cue ball and the shooter while in the act of shooting. If such an accident occurs, the player should
allow the Tournament Director to restore the object balls to their correct positions. If the player does not
allow such a restoration, and a ball set in motion as a normal part of the shot touches such an unrestored
ball, or passes partly into a region originally occupied by a disturbed ball, the shot is a foul.[B] In short, if the
accident has any effect on the outcome of the shot, it is a foul[/B]. In any case, the Tournament Director must
be called upon to restore the positions of the disturbed balls as soon as possible, but not during the shot.
It is a foul to play another shot before the Tournament Director has restored any accidentally moved balls.
At the non-shooting player’s option, the disturbed balls will be left in their new positions. In this case, the
balls are considered restored, and subsequent contact on them is not a foul. It is still a foul to make any
contact with the cue ball whatsoever while it is in play, except for the normal tip-to-ball contact during a
shot.