This feels like a failing of policing in general. It's not that much of an ask for a police officer to be able to articulate the law that a person is being ticketed/arrested for. It's also a failing that a police officer can just enforce their will against the public regardless if their actions are lawful or not, and the civilian has to argue in court or have a lawyer argue on their behalf to show that the cop's actions indeed were not lawful; and they'll still have to pay court costs.