What good would it had done if Jackie did say that? By now, she was basicly off the police force because of a back injury she had, and of course, out of uniform. If she was still an active police officer at that point, she would've threatened the guy in some manner. When the guy was insisting on dancing with Crystal, he would've probably backed off if he had a good clue she was an officer. Telling the guy "she has some friends on the police force" would've had much effect on the guy's behavior.