Perhaps there is a court ruling that created such immunity. (news.lawreader.com)
No civilized country, anywhere, provides immunity to lawsuits for defamatory speech (and its somewhat embarassing for an academic — who the naive might assume is committed to the persuit of truth (and civility)-- to be arguing for such immunity). (slaw.ca)
The Supervisory Authority and its officers and employees shall enjoy such immunity from legal or administrative process as is specified in the Protocol. (unidroit.org)