In United States v. Dyer, 722 F.2d 174, 177 (5th Cir.1983), the Court specifically noted that, as to the civil attorney, where the government met its prima facie showing the crime-fraud exception applied to remove the attorney-client privilege, the defendant still "retains his privilege to block the testimony of his civil attorney before the grand jury except as to the events immediately surrounding the preparation of the" letter at issue. 722 F.2d at 179.