Our camera's use lines to measure speed and flash from the front of the vehicle in South Africa. Last night I went thru a trap at exactly the posted limit, while I was pulling a single axle trailer behind my SUV. As I was in line with the camera, I was looking at it thru my passenger window the camera flashed me.

Can anyone explain why it flashed? Did the trailer confuse it?
I do not think I will get any ticket, as it would not have seen my plates when it flashed and I have photo blocker anyway. Just interested to know how these cameras work with the lines and why it flashed?

Appreciate any help

Cheers, PERCY-ZN