In libel and defamation actions it's a general rule that no remedy can be had for a statement that was issued in the form of an opinion.
The distinction between a statement of fact and one of opinion is frequently difficult. In characterizing a statement, courts must look at it not as lawyers and judges but by placing ourselves in the position of the hearer or reader, and determine the sense or meaning of the statement according to its natural and popular construction. In short, the measure is not the effect of the statement on a mind trained in the law, but by the natural and probable effect upon the mind of the average reader. (Baker v. Los Angeles Herald Examiner (1986) 42 Cal.3d 254, 260.) Accordingly, "what constitutes a statement of fact in one context may be treated as a statement of opinion in another, in light of the nature and content of the communication taken as a whole." (Gregory v. McDonnell Douglas Corp. (1976) 17 Cal.3d 596, 601.)
"For these reasons, California courts have developed a 'totality of the circumstances' test to determine whether an alleged defamatory statement is one of fact or of opinion. First, the language of the statement is examined. For words to be defamatory, they must be understood in a defamatory sense. Where the language of the statement is 'cautiously phrased in terms of apparency,' the statement is less likely to be reasonably understood as a statement of fact rather than opinion. Next, the context in which the statement was made must be considered. Since '[a] word is not a crystal, transparent and unchanged, [but] is the skin of a living thought and may vary greatly in color and content according to the circumstances and the time in which it is used,' the facts surrounding the publication must also be carefully considered.
"This contextual analysis demands that the courts look at the nature and full content of the communication and to the knowledge and understanding of the audience to whom the publication was directed. '"[T]he publication in question must be considered in its entirety; '[i]t may not be divided into segments and each portion treated as a separate unit.' It must be read as a whole in order to understand its import and the effect which it was calculated to have on the reader, and construed in the light of the whole scope and apparent object of the writer, considering not only the actual language used, but the sense and meaning which may have been fairly presumed to have been conveyed to those who read it. If the publication so construed is not reasonably susceptible of a defamatory meaning and cannot be reasonably understood in the defamatory sense, [the statement is not actionable]. (Baker, supra, 42 Cal.3d at pp. 260-261.)
Given the trial court's special role in ruling on dispositive motions in libel cases (the distinction between fact and opinion is a question for the court, not the jury) (Baker, supra, 42 Cal.3d at p. 260).