Business review on Google

I put a negative review on a business website. The owner, his son, and their family friend, husband and wife, put 5 stars, same day. So, I told them ,it is not a good practice to scam people, also customers need to be very careful when using credit cards for extra charges. Owtold me he will file complaint against me for harassing them, I never said anything bad. The owner cursed me. I was polite and respectful in my communication with them. He told me will call cops on me, the precinct officer called me, left a message on my phone. I don't even know if it is a real cop. I have not said anything bad, the review was honest opinion, they were being unethical. He is the one who threatened me. I told himbthat I am doing a citizen journalism and want a clarification on their reviews. Every communication we had is through chat and email. No calls. He called me but I did not answer. Do I have to call that cop back?