nly when it would achieve a public good transcending the normally predominant principle of utilizing all rational means for ascertaining the truth, Adidas v. Christie, 488 F.3d 1324 (11ih Cir. 2007), citing United States v. Nixon, 418 U.S. 683, 710, 94 S. Ct. 3090, 3108, 41 L.Ed. 2d 1039 (1974)( privileges are in