I am a movie director and I just received the following movie plot. Could you help me answer this question? If not, let me know by writing "Not answerable". Plot title: Duel Movie plot: David Mann is a middle-aged salesman driving on a business trip. On a two-lane highway in the California desert, he encounters a grimy tanker truck, traveling slower than the speed limit and expelling sooty diesel exhaust. Mann overtakes, but the truck roars past him and slows down again. Mann overtakes again; the truck blasts its horn and Mann leaves it in the distance. Mann pulls into a gas station, and shortly after the truck arrives and parks next to him. Mann phones his wife, who is upset with him after an argument the previous night. Several times the truck driver blasts his air horn, seemingly impatient at waiting to be served by the attendant who is attending to Mann. The gas station attendant refills Mann's car and mentions that it needs a new radiator hose, but Mann refuses the repair. The Peterbilt 281 tanker truck Back on the road, the truck catches up, overtakes, and blocks Mann's path each time he attempts to pass. After antagonizing Mann for some time, the unseen driver waves him past indicating it is safe to overtake, but when Mann attempts to pass he almost strikes an oncoming vehicle. Realizing the truck driver was trying to trick him into a collision, Mann passes the truck again, using an unpaved turnout next to the highway. The truck tailgates Mann at high speeds, forcing him to maintain his speed to avoid being rear-ended. After the truck bumps him several times, Mann drives his car off the road and collides with a fence opposite a diner. The truck continues down the road, and Mann enters the diner to compose himself. Returning from the restroom, he is shocked to see the truck parked outside. Mann studies the diner patrons and confronts the man who he believes is the truck driver; offended, the driver strikes Mann in the stomach and drives away in a different truck. The pursuing truck leaves seconds later indicating its driver was never inside the diner. Mann leaves the diner and stops to help a stranded school bus, but his front bumper becomes caught underneath the bus's rear... My question: What is Manns response to the wreckage?
A:
He laughs with glee and relief.