Gustafson v. Mazer
In Gustafson v. Mazer, 113 Wn. App. 770, 54 P.3d 743 (2002), the plaintiff brought an action for negligence and defamation against a psychologist who prepared a report for a child custody proceeding.
The Washington Court of Appeals found that generally, witness immunity is an absolute privilege. Id. The court further found that "'witnesses are immune from all claims arising out of all testimony.'" Id. at 775, 54 P.2d at 745.
The plaintiff argued that her suit was not based upon "the psychologist's testimony but, rather, on 'the psychologist's negligently premature and uninformed allegation of Munchhausen syndrome by proxy,'" and that therefore, no immunity should be afforded. Id. at 776, 54 P.2d at 746.
The court found that the psychologist's statements diagnosing the plaintiff with Munchhausen syndrome by proxy were afforded absolute immunity.