Right and it is never the cops role to know what can be sustained in his juris diction. And it is the usual thing for cops to go investigate a possible break in and arrest the legal resident.
Sorry, you are the one who needs to go live in the real world. The charges were dropped because it is not against the law to argue with a cop whether he warns you or not. A cop is not a petty prince and that is the real world.
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Again you display an astounding ignorance of both the facts of the case and the law itself.
If you are arguing with an officer (which btw is not the case here since only Gates was in argue mode) and that attracts a crowd of on-lookers (which was the case) then you have disturbed the peace (again, look it up). If you are then told by the officer to desist (a lawful order - again, look it up) and refuse then you are subject to arrest.
The legal definitions are out there...do a bit of work. The facts of the case are out there...do a bit of work. Or, you may, as I bet you will, just pull nonsense out of your ear and then argue it as fact. That is easier but fairly stupid.