Simply putting a fake plate would bypass that. Truckers usually have a pulley system on their plates to avoid tolls, so maybe more normal drivers will implement such a system or find a way to create something that messes up their camera OCR.
That would probably flag you immediately for a plate that doesn't match the car, a plate that does match but seen in two places that would be impossible to travel in that time.
That event would go in the same bucket as the other ten million alerts where the system got confused between visually near identical models or some de-badged sports car.
The fact of the matter is that the powers that be can't overtly use the dragnet in the way that the "how dare someone skip a $2 toll" and "muh two ton death machine" crowds would like to see because the other 99.5% of the public will be all "hey WTF" and politicians will pass laws to pander to those people. The dragnet operating powers that be would rather retain the ability to use the dragnet unfettered even in bad ways so they normally reserve its use for "serious" things.