eferring to United States S.C. I Nobles, 422 U.S. 225, 95 . 2160, 45 L.Ed.2d 141 (1975). Duplan, 540 F.2d at 1223. Of course, the subject of the Duplan case was the ex- tent to which the inadvertent or partial pro- duction constituted a waiver, and if so, whether additional discovery of protected m