The problem with all the “know your rights” cards/videos/articles is that most of them ignore the harsh reality of the balance of power in a “custodial interrogation.” The police have all the power and can be extremely intimidating. This is especially true if you are a member of a disenfranchised class.
So in most cases the cop won’t say “Will you empty your pockets for me?” because this implies that you can refuse. Instead he will, as in the example, say “Do me a favor, sit there and empty your pockets” which makes it seem like you have no choice. And if you try to argue, he will probably come back with “alright, well I already got you boys on not wearing a seatbelt, illegal lane change and now it sounds like you’re asking for disorderly conduct, so we can do it the easy way or I can take you down to the station house and we can do it the hard way.”
Because remember, when you are stopped on the streets it doesn’t matter if the cop violates your rights or trumps up charges or performs illegal searches, because he can still throw you in jail, fingerprint you, make you pay bail and get sent to court. Even if the charges are dismissed in court, you still have a mugshot, your name was in the newspaper, you had to miss work for court date and possibly hire an attorney. These things can often cost someone their reputation/job/scholarship.