It is my understanding that police can say whatever they'd like and it's your job to know your rights.
Just like no cop will get in trouble for telling you OC is illegal so cover up.
Just like no cop will get in trouble for telling you to step out of the car and then demanding to search it.
Its up to you to know your rights, apply them, and then fight for them in court if the cop decides to be an ass.
This information is worth exactly what you paid for it, and I strongly suggest you get a lawyer/officer's opinion.