If you are wondering why is she not handcuffed and restrained at the time of arrest, you have to look the surrondings very well. There is not even a single female police officer present in the station. Without the presence of a female officer one cannot take a female into custody physically.
It is against the rules and regulations. Slapping government personals on duty especially if he is in uniform is against the law and the person who attacks do get charged. we have to apply simple common sense here before deciding the girls’s character.
Till end they didn’t do anything against the girl that means she is angry because cops must have done something to her. Also notice the policeman surronded the girl. They are also acting in a strange manner.