They were in the intersection and should have went through. Here in SC USA you may
never reverse in or at an intersection unless specifically directed to do so by authorized emergency response personnel
Nor may anyone else enter the intersection until any cars already in it go through, regardless or whether they have a green, yellow, or red light. And you are not permitted to reverse for more than 50 ft on any public roadway- instead you must turn around to change direction
People who cannot understand such simple rules are unfit to drive, and persons who knowingly license unfit drivers are unfit to be breathing
Phil