In the case of Holguin-Hernandez v. United States, 2019, the defendant was convicted on drug charges and sentenced to five years in prison. He appealed his sentence arguing that it was unreasonably long. The Fifth Circuit Court rejected his appeal stating he had not raised an objection about the length of his sentence during sentencing proceedings at trial court level. However, when this case reached the Supreme Court, they unanimously ruled in favor of Holguin-Hernandez stating that a formal objection regarding a sentencing error is preserved as long as the party informs the court of its opposition to proposed action (here being lengthier imprisonment). This ruling clarified how defendants can preserve their right to challenge sentences on appeal by simply expressing disagreement with decisions made at trial courts.

In the dissenting opinion for Holguin-Hernandez v. United States, Justice Alito argued that the majority's interpretation of Rule 51(b) was incorrect and could potentially lead to confusion in lower courts. He contended that a defendant must object after sentencing to preserve a claim of procedural error on appeal, even if they had already objected before sentencing. According to him, this requirement ensures that district judges have an opportunity to correct any errors before cases reach appellate courts. Furthermore, he disagreed with the majority’s view about what constitutes an “opportunity” for objection under Rule 51(b). In his perspective, defendants should be required not just to state their disagreement with a sentence but also explain why it is unreasonable or procedurally flawed at the time of pronouncement.