Now getting back to the original question.
From the official rules of cuesport international - BCAPL official rules.
1-38 Ball In Hand Placement (also see AR 1-7, Beginning of Game or Match) General Discussion: With cue ball in hand, the freedom to place the ball anywhere on the table does not include placement of the ball for the purpose of measuring a gap between balls, between a ball and a cushion, or in an attempt to determine whether a ball can be contacted before another ball. The provisions of Rule 1-3-1-g apply to ball in hand placement, and a foul may occur if any particular use, placement or motion of the cue ball, while in hand, violates that rule. It is not necessarily a defense against a foul for a player with ball in hand to use the cue ball in such a manner, and then claim that they were considering shooting from a particular position and changed their mind.
Whether a foul has occurred in such a situation is at the sole judgment of the referee.
Rule 1-38-3: If the referee picks up the cue ball to give it to a player for ball in hand and disturbs one or more balls when doing so, they must be restored by the referee.
1. Situation: Player A, with ball in hand, drops the cue ball into a pocket or knocks it into a pocket before executing a stroke. Ruling: Player A still has ball in hand.