Here's the real context. Parking officers don't work at midnight normally, which means someone called the cops on you after hours. The cop would be forced to tow you (at after-hours pricing) and went beyond their minimal obligations to contact you first.

As for whether this is considered harassment - it wouldn't even be considered harassment by a private citizen. Like it or not, this is the United States and the bar for harassment by a police officer is incredibly high. Most people try to be polite and deferential to police officers because they can legally make your life a living hell.