Derek you ask for Zirik to remove his post? Why? Are you going to claim that the his post is protected by an NDA? His post contains nothing of your conversation with Kxmode over email at all. Are you going to threaten Blue or Zirik with your teams of lawyers?
I hope you are joking. Next thing all employers will start threatening their former employees/contractors because of what negative things they say about the company they were formerly employed or contracted by.
In the USA we still have a right to criticize our employer. It's madness to think otherwise. As you are probably aware of the truth is an absolute defense against defamation. If it's true that KXMode did not get paid and he has the emails that show how you brutishly responded to him, then Zirik quote stands on solid ground against any potential allegations of defamation.
This the Internet: people post comments about products or services and other people. Is that defamation too? If everyone threatened legal action in the age of the internet, the courts would have nothing but defamation suits to handle. Why don't companies start suing people for their negative reviews of products or services? People post emails and even record conversations between customer support over various issues product or services on websites like consumerist.org all the time. By your logic consumerist.org should have been sued to oblivion by now.