The case of Vladimir Zatko v. California in 1991 revolved around a dispute over the application of the "mailbox rule" to habeas corpus petitions. The mailbox rule states that a document is considered filed at the time it was delivered to postal authorities, not when it was received by its intended recipient. Zatko, an inmate in California state prison, had mailed his petition for habeas corpus (a legal action through which detainees can seek relief from unlawful imprisonment) on the last day of his one-year filing deadline as stipulated by federal law. However, due to delays in mail delivery and processing times within the court system, his petition wasn't officially stamped as 'filed' until after this deadline had passed. Zatko argued that under the mailbox rule his petition should be considered timely because he'd submitted it on time according to postmark date; however, lower courts ruled against him stating that such rules didn’t apply here since they were designed for civil cases rather than criminal ones like habeas corpus proceedings. Upon appeal though,the Supreme Court disagreed with these rulings and sided with Zatko's interpretation instead - thereby affirming applicability of mailbox rule even for habeas corpus filings.

The dissenting opinion in the case of Vladimir Zatko v. California argued that the majority's decision to uphold Zatko's conviction was inconsistent with previous Supreme Court rulings regarding police misconduct and its impact on a defendant’s right to a fair trial. The dissenting justices believed that there was substantial evidence suggesting that law enforcement officials had manipulated or fabricated evidence against Zatko, which should have been enough to warrant a new trial under established precedent. They also expressed concern about the potential implications of this ruling for future cases involving allegations of police misconduct, arguing it could set a dangerous precedent by effectively lowering the standard for what constitutes acceptable behavior by law enforcement during criminal investigations.