They are supposed to be in New England, yet at the end, there is a palm tree next to the golf course.
After Jason's parents decide to leave following the discussion, Lorelai says that she is blocked in even though she arrived at her parents' house after Rory and Jason.
When Dean comes to bring Rory the bookcase he looks around and says "There's nowhere to put this" but right behind him there's a perfect spot if two very small items are moved out of the way.