In the case of Joseph C. Roell, Petra Garibay, and James Reagan v. Jon Michael Withrow (2002), the U.S Supreme Court addressed whether a federal magistrate judge could exercise jurisdiction over a civil case based on implied consent from parties involved. The dispute arose when Withrow sued his former employers for wrongful termination under Americans with Disabilities Act (ADA). Initially, both parties agreed to have their trial before a magistrate judge but later defendants claimed they never explicitly consented in writing as required by law. The Fifth Circuit court ruled in favor of defendants stating that explicit written consent is necessary for jurisdiction while ignoring any form of implied or verbal agreement. However, the Supreme Court reversed this decision arguing that nothing in Federal Magistrates Act demands express written consent and it's not unconstitutional to infer such an agreement from party actions or conduct during proceedings before magistrate judges. Therefore, if all parties participate fully without raising objections at any stage then it can be considered as implicit acceptance granting authority to presiding magistrates.

In the dissenting opinion for Roell v. Withrow, Justice Scalia argued that consent to a magistrate judge's jurisdiction must be explicit and on record, not inferred from conduct as the majority held. He emphasized that federal law requires clear and unambiguous consent in order to ensure fairness and avoid potential coercion or misunderstanding. The majority’s decision to allow implied consent undermines this principle by introducing uncertainty into what should be a straightforward process. Furthermore, he criticized the court's reliance on "pragmatic" considerations rather than adhering strictly to statutory requirements. In his view, it is not within the Court’s power to alter these rules based solely on practicality or convenience.