In most activites in life, the police are never called.
A too loud party or music is a general complaint of the public. Sooner or later, if the party lingers past midnight, the police will be called to quiten the noise.
Most people expect and understand this situation and that takes care of the problem.
What about a couple arguing and throwing objects at each other? Is this a different situation? Yes, because the potential of bodily injury may occur. So, how do we look at this situation, compared to the loud party? They are entirely different.
In this last case, THEN, the police appear and the complainant and everyone else knows that someone is going jail. Its the law on domestic violence.
Each case is different and has its own merits.