Holden's mother gives him a copy of _Don Quixote_, but the book in the scene is entirely too thin. DQ is a massive novel of almost a thousand pages, so the book should have been anywhere from one-and-a-half to two-and-a-half inches thick, depending on the size of the font. To fit in the book that Holden has, the font would have had to be read with a magnifying glass.
Holden's mother says "Storm's coming". The lightning and thunder are simultaneous meaning the storm is already directly overhead and very low. In fact the thunder seems to be slightly ahead of the lightning, which is impossible in real life.