Is this true though? Earlier today mine picked up on emergency lights that were several hundred feet further away in traffic than I would have seen them. It seems able to enhance the images the cameras capture.
Could also be aware of the position of fixed road equipment via mapping software. It's more plausible than the cameras having some kind of super vision.
Realistically the training data contained some amount of emergency lights through fog, so it can identify faint emergency lights through fog as real emergency lights and will appropriately display the warning on-screen.
Also, WAZE and Google maps have had user reported speed traps for some time. So 1 Tesla driving by information the network of the police car and others do not need to observe it to know it's there