What is the government's single-witness policy in this grand jury proceeding?

As we see it, there is a great deal to criticize in the government's handling of this grand jury proceeding. The single-witness policy routinely relies on hearsay, producing " 'evidence' which appears smooth, well integrated and consistent", making even weak cases appear strong. United States v. Arcuri, 282 F.Supp. 347, 349 (E.D.N.Y.), aff'd, 405 F.2d 691 (2d Cir.1968), cert. denied, 395 U.S. 913, 89 S.Ct. 1760, 23 L.Ed.2d 227 (1969). It also "prevents the defendant from utilizing grand jury testimony in cross-examining witnesses who will testify at trial". Id. at 349-50.