In the case of Digital Equipment Corporation v. Desktop Direct, Inc., 1993, the US Supreme Court ruled on whether a denial of summary judgment that turns on an issue of law is immediately appealable under section 1291. The court held that such denials are not immediately appealable as they do not constitute a "final decision" within the meaning of section 1291. This ruling was based on Cohen's collateral order doctrine which allows immediate appeals from orders that conclusively determine disputed questions separate from the merits and effectively unreviewable later in litigation. In this case, Digital Equipment Corp had sought to dismiss claims by Desktop Direct Inc under Rule 12(b)(6) for failure to state a claim upon which relief can be granted and then moved for summary judgement when their motion was denied but both were rejected by lower courts before reaching trial stage. However, according to Justice Souter who delivered majority opinion, neither rejection constituted final decisions thus could not be appealed until after trial verdicts.

The dissenting opinion in the case of Digital Equipment Corporation v. Desktop Direct, Inc., argued that the majority's decision to deny immediate appeal from a district court's denial of a motion for summary judgment based on qualified immunity was incorrect. The dissent believed this ruling would lead to unnecessary and costly litigation by forcing parties to go through full trials even when there may be clear grounds for dismissal at an earlier stage. They contended that such denials should be immediately appealable under the collateral order doctrine, which allows appeals from certain interlocutory orders. This view held that denying immediate review could potentially expose public officials or entities to unwarranted disruption and expense associated with trial proceedings, contrary to the purpose of qualified immunity protection.