Is this not something they anticipated? Is it rare enough that they just don't care[0]? Can it not be "fixed" to avoid this problem[1]?
[0] It's reasonable to ignore low probability events that can be dealt with by a suitable process, but the scenario should be analysed.
[1] See point [0].
I’ve never received an automated speeding violation, but have received turn-on-red ones before. In those cases, the violation includes a link where you can see a video of the whole scenario and offers a button to click where you claim it was not actually a violation. Hopefully the speed cameras also have such a system where you have some reference points to calculate time travelled between frames in the video (with a know frame rate).
What if there just happened to also be a slow car in the photo? How do you prove that the reported speed is that of the duck and not of the car?