You should go to Muroor in Gharafa and the Office is located above the license renewing section. The chances of being caught in the camera while crossing the line in green and yellow is almost impossible. The camera will start flashing only when the red light is on and the rear tyre of your car is behind the sensor line. If your father has crossed the sensor line when the signal was yellow the camera will not flash. If your car is fully out of the sensor line before the red signal the camera will not work. You can go to Muroor and check it yourself. If you are going to argue with them they will not give any discount and try to be polite and request for a reduction and you might gain. If your car was out of the sensor line before it is red then they will not charge you but the chance is very rare for such an incident.