If you get saved for Zul'Aman and leave the instance for at least 30 minutes (soft reset), then the front door ( the one that opens after you hit the gong) is gonna be closed, which means you cannot access the instance any more, unless you bug through the door somehow (like blink), since Harrison Jones is not gonna be there any more and you cant hit the gong for second time.
If you get saved for Zul'Aman and leave the instance for at least 30 minutes (soft reset), then the front door ( the one that opens after you hit the gong) is gonna be closed, which means you cannot access the instance any more, unless you bug through the door somehow (like blink), since Harrison Jones is not gonna be there any more and you cant hit the gong for second time.