They don't land planes at KSAN in the fog, because of the steep decent. So it would have ended very differently, because that Citation would have been diverted

They don't land planes at KSAN in the fog, because of the steep decent. So it would have ended very differently, because that Citation would have been diverted elsewhere. Real error here was that SWA should have been told to hold short and then expedite as the SWA boys like to do after Citation was clear or to expedite from the getgo. Both would have worked just fine. Also worth mentioning that while you can give landing clearance onto a runway that is not clear at the time, you still cannot have multiple aircraft on a given runway simultaneously, and there are very strict minimum separation requirements that vary depending on the airport which for KSAN is 5NM