Since you state that you know the law you shouldn't need reminding that it's an offence to go through an amber light unless it's unsafe to stop. The excuse of 'unsafe to stop' is only valid for amber lights, not red ones.
Telling the authorities that you were travelling with an insecure load (which could have shot forward under sudden braking) would effectively be admitting to an additional offence, so it would seem unwise to do so!
Anyway, if you didn't see a light flash you're probably safe. The majority of traffic lights aren't fitted with cameras. (The boxes you often see on top of traffic lights are radar detectors, sensing approaching traffic, not cameras). If a camera is fitted you should see a bright double-flash if you cross the white line even a tiny fraction of a second after the lights have gone red. (Even though the flash is behind you it's usually bright enough to light up the inside of your car via your mirrors).
Chris