In the case of United States v. Guy W. Olano, Jr., and Raymond M. Gray (1992), the U.S Supreme Court was tasked with determining whether a trial court's error could be corrected on appeal if it had not been objected to during the trial itself. The defendants, Olano and Gray, were convicted for various offenses related to their roles in a failed savings and loan association but argued that they should have received separate trials due to prejudicial joinder - an issue they did not raise at their original trial. The Supreme Court held that under Rule 52(b) of Federal Rules of Criminal Procedure, an appeals court can correct errors which are plain and affect substantial rights even if these errors were not brought up at trial; however, this is discretionary rather than mandatory power given to appellate courts by Rule 52(b). In this particular case though, the Court found no such error affecting substantial rights as there was no reasonable probability that without the alleged error things would have turned out differently for either defendant.

In the dissenting opinion for United States v. Guy W. Olano, Jr., and Raymond M. Gray, Justice Blackmun argued that the majority's interpretation of Rule 52(b) was too restrictive and could potentially undermine defendants' rights to a fair trial by limiting appellate courts' ability to correct certain types of errors. He contended that any error which affects substantial rights should be considered "plain" under Rule 52(b), regardless of whether it was objected to at trial or not. Furthermore, he disagreed with the majority's view that an error must affect the outcome of proceedings in order to warrant correction; instead, he believed an error can still seriously affect fairness, integrity or public reputation even if it does not alter results directly.