Defences to defamation include fair comment, justification, and qualified privilege.
Fair comment: A comment is the subjective expression of opinion which is generally incapable of proof. In order to be fair, it must be shown that the facts upon which the comment is based are truly stated, and that the comment is an honest expression of opinion relating to those facts. The comment must be made on a matter of public interest.
Justification: If a person being sued for defamation can prove that their comments were substantially true, they have an absolute defence to the plaintiff’s claim of defamation. This means that a person offended by the remarks will not be able to win their defamation case.
Qualified privilege: If the statements were made on an occasion where the person who makes a communication has an interest or legal, social, or moral duty to make it to the person to whom it is made, and the person to whom it is so made has a corresponding interest or duty to receive it, the presumption that the defamatory statement was malicious is rebutted.
Another important note is that a full apology, made before the commencement of the defamation action, can mitigate (lower) the damages that a person may owe. A prompt apology may reduce the risk for the defendant, and the potential reward for the plaintiff.