The book is the same. And he knew it was unrealistic. He even considered an alternate opening, where the MAV malfunctions. He figured he had been so accurate everywhere else, that he could afford one mistake. It was a Man vs Nature story, and he wanted Nature to have the first punch.

(The one other inaccuracy he admitted to was the radiation on the surface of Mars. Watney likely would have gotten cancer before he was even rescued. In the book, he said that there was radiation shielding in the Hab and the spacesuits, but nothing that could block radiation would have fit in so thin a material.)