Khan observes that if flight 409 is cancelled, then the manager could not possible arrive in the time for the meeting . But the flight was not cancelled. Therefore, Khan concludes, the manager will certainly be on time . Halima replies that even if Khan's premises are true, his argument is fallacious. And therefore, she adds, the manager will not arrive on time after all. Which of the following is the strongest thing that we can properly say about this discussion ?