Logic

The director of a company wakes early for a morning flight. He realises he forgot some papers at work and goes there. In the office he meets the night watchman, who is leaving for home. The watchman stops the director, tells the director he shouldn't fly. "I had a dream last night," the watchman says. "I saw you crash." He takes the director's hand. "I saw you die sir. I saw you die." The director heeds the advice and sure enough the goes down. The next day the director returns, gives the watchman a generous bonus. Then he fires him. Why?