(b) Neither the sheriff, the county commission or community service agency to which the person is assigned shall be liable for injury or damage to third parties intentionally committed by the person so sentenced or for any action on behalf of the person so sentenced except in the case of gross negligence on the part of the sheriff, county commission or community service agency or the supervisor of the person so sentenced: Provided, That nothing herein shall bar a claim by a third party for injury or damage resulting from the negligent act of the person so sentenced committed outside the confines of a county jail and within the scope of the work required by the alternative sentence.