Internet

Can I be sued for posting an unsatisfactory review on a website?
I had posted a review on a website regarding a law firm that I had once worked for. The review was an unsatisfactory one due to my opinion of the firm. At the time of writing the review I was just being honest and giving my own personal opinion, thinking that this was allowed due to my freedom of speech. I do not know if the reviews on that site are monitored, but the review was posted. The website only offered my first name and last initial; however, the law firm contacted me and threatened to pursue legal action on account of slander and defamation charges. At first the attorney asked that I remove the review and post a retraction. I followed through with this on the same day of his request. Now the only review that is on that website is a revised review with no bad remarks whatsoever. Even though this is the only live content on that site when a search is performed on Google.com a result which includes the introduction of my old review appears. But, when this result is selected it only takes you to the new revised review. I have contacted Google to request that this result be removed from their search index. I was told that it usually takes 4-6 weeks for their system to update and that the webmaster of the site would have to send in a request to have it removed. I have emailed the webmaster asking for this to be done and sent step by step instructions on how to do so, but have not yet received a response on whether or not they will do this. The attorney contacted me the other day and said that since the review was not removed they are pursuing legal action against me. I am assuming that he is referring to the search result that I mentioned earlier. The attorney and I have only been in contact via email. I sent him an email yesterday asking what website he is referring to and reassured him that the old review was removed and a retraction was posted in its place. I have not yet received an answer from him so I am still unsure of what exactly he is talking about. His last email to me suggested that I should hire an attorney and that he would rather be in contact with my attorney from this point forward. With this said, I have the following questions: 1. Does this firm actually have grounds to take legal action against me? 2. What are the specific slander and defamation laws for NC? 3. Are there any other laws regarding the fact that this review was posted on the internet? 4. Does the fact that I was once employed by this firm cause any additional problems for me?