I'd say it's human error by both the tower and the pilot.
The lights are controlled by the tower, however, if both runways are active, then they would have both on.
The tower also tells the pilot where to go. The tower could have told the pilot the wrong runway on accident, or the pilot misheard the tower and proceeded on the wrong runway. This should have been picked up by the tower, who are supposed to be watching the airfeild...
