The night watchman

A great CEO, Mr. Dupont, has his watchman supervised by a night watchman. He must go on a trip, but the morning of his departure, his night watchman said to him:

- Sir, do not leave. That night, I dreamed that your plane crashed.

Mr. Dupont cancels his trip and learns in the evening, that indeed the plane crashed. To thank his employee, he gives him a large sum of money, but nevertheless, fired him. Why ?

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