Basically I feel like the police needn't be involved and that officer probably should have read the Yelp posts prior to calling, I highly doubt this would ever go to trial.

The cops shouldn't have read the reviews and shouldn't have called nor had any interest in this case.

This is incompetence (failing to understand the law) at best, or a cop making an unofficial call to intimidate a citizen as a favor to the pizza place owner at worst.

Either way, there's no good reason for the cops to get involved at all here.