When said sarcastically, it's telegraphing a disaster. When said more seriously, it's an open invitation for the world to go to hell in a handbasket. Say there is one critical thing that could happen that would cause a catastrophe that, left unchecked, would directly or indirectly result in disaster. But everyone in the story is assured that this critical thing will never, ever happen. Ever. The audience knows better. In the event that someone in the know tries to warn his superiors to get the situation fixed, expect them to be flat out ignored. Examples of What Could Possibly Go Wrong? include: