Lights left on highway

Hello fans, my 120 km/h was shown at night on the BAB as above! Was overtaken by car on the left and then it flashed 2 times red in the height of the overtaking, who had to be faster than me! But: The red flashes came from the left, so from the direction of the middle guard plank??????? How does so and why? Has someone allowed himself a joke and flashed out of the car, because I drove the 120…? How does a speed camera get to this point in the traffic? Does anyone have an idea??? Thanks and Greetings, NT