The Appeals Court ruling that Murtha was immune from a lawsuit because the remarks were made as part of his official duties is bullsh*t as well.
First of all, Murtha was making gratitous unfounded accusations apart from his duties as a congress critter, just as the new defamation suit claims.
Second of all, even if they were made as a part of his genuine duties, the accusations were so reckless and over the top, this defense would not stand. Recall exactly the same defense being made in the Nuremberg Trials and said defense being dismissed because the actions of the accused were so far beyond the standards of normal, civilized behavior that the worst of the lot were hanged anyway.
Under the appeals court standard, the only one who would have been hanged was Julius Streicher, because he was the only one of the defendants acting outside official nazi government capacity.
Under the U.S. Constitution, Article I, section 6, "for any Speech or Debate in either House, they [Senators and Representatives] shall not be questioned in any other Place."