I have posted a couple of other videos on this thread that explain it a lot better than I can in a few paragraphs. They are pretty long, but very interesting whether you agree with the application or not. It's pretty simple, but it's a deceit that makes it complicated.
Basically, he doesn't have the authority to order you to do anything. If he gives you an order you can present him with a bill for fulfilling that order. It's only when a policeman doesn't suss that the person he is talking to has a better understanding of how the system works than he does that it becomes really interesting.
The reason for this is that, although he doesn't understand it (and you can't blame him because he isn't taught the true meaning of the law), a judge will understand what you are doing, and will try to put the matter to bed as quickly as he can, ie. throw the case out before it costs the state a fortune, and before it becomes a big enough deal for people to notice. They don't want you to notice.
Case Law has nothing to do with it. This is based on precendent between 2 or more parties that have submitted to have their case arbitrated by a judge. The law of the land, or Common Law literally boils down to a person actually causing damage to a person or their property. It does not include engaging in activities that MAY cause damage to another person. The police are well within their rights to try to prevent you causing harm, but have no authority until you have Actually done so.
Statutes are "laws" based on Acts which are passed by Parliament. They are written in a very specific legal language, that you are incapable of understanding unless you have studied Law at degree level or above. You don't have to submit to anything you don't understand, so why would you?
I'm not absolutely sure who discovered this, but there is growing movement of people who call themselves Freemen who use this information at every oppurtunity and believe it or not some of them are very popular with the more Senior members of the Police Forces of their respective countries. The reason being, if you ask a decent Policeman if he joined to a) help people or b) collect revenue, you can pretty much guess what the answer will be. We won't lower ourselves to aknowledging those who answer c) to give people a good slap every now and then.
Once a decent but jaded Police Officer has had the time to cool down and think about it, they realise that if more people understood the way the law works (the truth of it) that they don't have to be the big bad copper anymore. They can now go back to doing what they are supposed to do - help people who need help.