How does Ausable manage to make Max believe that there is a balcony attached to his room? Look back at his detailed description of it. What makes it a convincing story?

Ausable created a convincing story about the presence of a balcony. He said that twice in a month somebody had entered his room through the balcony. On being questioned by Max about the balcony, he replied with extreme irritation that it was not his balcony. This reaction, which looked natural, played a part in convincing Max. He further told Max explanatorily that his room was earlier a part of a larger unit and the adjoining room was the one which had the balcony. He said that it extended under his window. His manner of description and speaking convinced Max that there was indeed a balcony under his window.