In Persona 5, after you
steal Okumura's Treasure, his Shadow is killed by an unseen assassin. This happens in the very same cutscene, literally two seconds after the Phantom Thieves have left the room.
By my understanding, this should have resulted in
an immediate mental shutdown.
And yet nothing happens until
the press conference on October 12th. Depending on how long it took you to clear the Palace, that's up to three weeks later.
Now, I understand that the out-of-universe reason for this is that if
Okumura had died the moment you cleared the Palace
it would have completely messed up the game's timeline of events. But in-universe, it doesn't make sense, especially considering that
the villains were relying on Okumura dying at exactly that moment, in order to implicate the Phantom Thieves in his death.
How should this be reconciled? In-universe, why didn't this character die immediately?