This is completely believable to me because something similar happened to me. I left a mildly worded 3-star review of a B&B and received an outraged personal email from the owner, complete with suggestions of karmic retribution.

The owner had my email address because I had emailed her originally to reserve the room. She figured out who I was because I had included details in the review about the problems I encountered.

I responded (mildly!) to her email, pointing out that my review was honest and not even all that bad, and suggesting that she post a management response on Trip Advisor. She responded with an even angrier email. I then told her concisely to stop emailing me, after which she emailed again and I ignored it.

I emailed Trip Advisor about our exchange, asking if the site had any rules against hotel owners directly contacting reviewers. They claimed that they did, but when I looked at the info they have for owners, I couldn't find any clearly written rule against personal communications about a review.

Trip Advisor asked me for details, but I decided to walk away. I figured the B&B owner's behavior would do enough damage to her business on its own and I was trying to enjoy my trip. In retrospect I should have gone through with a report.

Later I saw that three 100% positive reviews had been published in quick succession right after the nasty emails, all from people who had no other reviews on Trip Advisor.