Sealed files don't require warrants they are just court records that aren't publicly accessible. My understanding is motions (appeals or some other proceeding?) can be filed by a defendent (if that's the right term) and prosecution has a limited time frame to respond. Defense lawyers will just file bogus motions hoping a deadline is missed and they can move things further along. When that happens, it makes even more work for prosecutors which eats up time they could be spending building cases