What if the ball is put in play on an IP? Does the team at bat get to choose between play and ball?
Rule 6.3.N USA softball
Effect – Section 1[A-E]: Illegal Pitch.
1. If the batter hits the ball and reaches first base safely, and if all other runners have advanced at least one base on the battered ball, the illegal pitch is nullified. All action as a result of the batted ball stands. No option is given. When a runner passes a base, the runner is considered to have touched the base.
2. Otherwise the manager has the option to take the result of the play, or the illegal pitch is enforced by awarding a ball to the batter and advancing all runners one base.
3. If an illegal pitch hits the batter out of the strike zone, the batter is awarded first base and all other runners are awarded one base.