When Lorelai and Rory are outside the Gilmore's house, Rory says that they have not had dinner with them in three weeks. However, in Partings (2006) Emily says that they were leaving for Europe for the next two months.
At the Friday night dinner Richard is holding a glass, but in the next shot he's holding a spoon.
Within the episode, they mention several times that this was Lorelai's First Cotillion. But in the episode Presenting Lorelai Gilmore (2001) Christopher says that he and Lorelai went to 17 cotillion, a dozen débutante balls and a brief but scarring experiment with the children of the American Revolution when they were young. So, this would indicate that Lorelai had previously gone to at least 17 other cotillions.
When Lorelai is talking to Rory about Pop Tarts, her arms change positions between shots.
Rory is seen tutoring a student for the SAT by working on an analogy question. The current version of the SAT does not include analogies.
It seems like Christopher addresses Lorelai as "Lauren", which is the actress' real name, but he really says '...Lor, and...'
When Lorelai and Rory are sitting, waiting for their drinks, you can fully see the bar cart but Charlotte is missing from the background while she is supposed to prepare drinks.
Rory says she's never been to a cotillion, but that she had a coming out party. Debutant balls are considered a cotillion, and many of them have the word in their name.
When Emily introduces Lorelai and Rory to Charlotte at Friday night dinner, she introduces them as 'my granddaughter and her mother.' This makes it seem as though Lorelai is not related to them, she is merely Rory's mother. Emily should have said they were her daughter and granddaughter.