If there is a legal requirement in this jurisdiction for citizens to retreat and try to escape BEFORE engaging in any self defense, THEN YES, the officer should have been legally obligated to approach the house and try to determine what was really going on before issuing a citation. There could have been legitimate reasons (or even an emergency situation the police officer might have helped to resolve?) the man left the car unattended and the officer didt even attempt to gather any further information.
Legal robbery by the state. Nothing more.
Exiting the door tomorrow with a shotgum when the cop is 4 or 5 steps up your driveway asking him what the hell he is doing on your private property might be entertaining.
I wouldn’t support threatening a cop with a shotgun.