It is a defense to prosecution, under this subparagraph if the owner, operator or employee of the establishment immediately upon discovery of a minor reasonably believed to be in violation of Sections 27-8-2 or 27-8-3 notified a law enforcement agency that a minor was present on the premises of the establishment during curfew or truancy hours and refused to leave the establishment after being advised to do so by the owner, operator or employee.