You know, I disagree with this line of thought more and more every time I read it.
Most Americans teach their kids to respect and trust police officers. Yet now we have courts routinely finding no problem with these police officers engaging in actions that would be illegal if they were "demands" but not if they are "requests".
Not only is it impossible to teach kids to distinguish this difference, is this really what the Law Enforcement Community as a whole wants the general public to become aware of and learn to do for themselves as well? Legal or no, refusing to answer, and walking away from a police officer engaging you in conversation is at the least rude, and if you are dealing with a bad attitude, may get you in serious trouble. And you absolutely can't teach your kids to respect and trust someone in some situations, but ignore and walk away in others. Sometimes getting what you ask for is not a good thing.
It seems to me it would be a whole lot better to train the police officers to just obey the law, both letter and spirit, and not give them a ridiculous "demand vs. request" loophole that allows them to abuse the rights of law abiding citizens.