You are probably right. I don't think they have to charge you, but they do have to have cause. If there is video that they detained you without cause. I may have gotten my terms mixed up. In my understanding. Cause, is suspicion of a crime (disorderly conduct and resisting arrest are most commonly abused). Charge is the documentation of an accusation from the police of you breaking a law. The police also have to (are supposed to) document this interaction even if they don't charge you with a crime.