In Silber v. United States, the Supreme Court examined whether a defendant's right to counsel was violated when his attorney was not allowed to be present during grand jury proceedings. The case involved an individual named Silber who had been indicted for perjury by a federal grand jury in New York. During the investigation, he requested that his lawyer be present while he testified before the grand jury but this request was denied and he subsequently appealed on these grounds after being convicted of perjury at trial. The Supreme Court upheld Silber’s conviction, ruling that there is no constitutional requirement for defense attorneys to be present during their clients' appearances before a grand jury. It reasoned that since the purpose of such proceedings is merely investigative rather than accusatory or adjudicative, they do not fall within Sixth Amendment protections guaranteeing defendants’ rights “to have Assistance of Counsel for his defence” in all criminal prosecutions.

In the dissenting opinion for Silber v. United States, it was argued that the majority's decision to uphold Silber's conviction under Section 145(b) of the Internal Revenue Code was incorrect. The dissenting justices believed that there wasn't sufficient evidence to prove that Silber had willfully attempted to evade or defeat his income tax. They pointed out inconsistencies in how "willfulness" is defined and applied in different cases, arguing for a more stringent standard where clear proof of intent is required. Furthermore, they disagreed with the majority’s interpretation of Spies v. United States which led them to conclude that any conduct leading to an understatement of tax could be considered as evasion attempt; instead they insisted on a narrower reading requiring specific actions such as keeping double books or making false entries etc., indicating fraudulent intent beyond mere understatement.