 DATE: After the escape, when many of the escapees are recaptured,  they are loaded onto trucks and deceived into thinking they were  being transported back to the prison camp. Along the way the trucks  stop so that the prisoners can have a break. When one of the trucks  stops, its brake light illuminates, and is clearly visible to the  viewer. Stop lights were not used in the early part of the 1940s,  and did not come into general use until the fifties.