Continuity mistake: Kirk did not know who Miss Patty was. He said "I wasn't aware that you were THE Miss Patty." Later in the series, in Episode 5 of Season 6, at Miss Patty's Grand Recital, Miss Patty introduces Kirk's performance and says that he was "a talented pupil of mine". His performance was titled, "20 Years Ago Today", therefore Kirk was a student and should have known who Miss Patty was all along.
Visible crew/equipment: After Rory tells Lorelai that she looks happy, when it cuts to Max telling his class about Emily Dickinson's poem, we can see the boom mic bobbing around at the top of the screen. (00:07:55)
The Fundamental Things Apply - S4-E5
Continuity mistake: Lorelai is in Luke's Diner talking to Luke. Lorelai is wearing a red sweater vest over a white blouse. When Luke is behind the counter, every time the camera faces Lorelai, the left side of her blouse goes from being tucked in under the vest (as if the vest were hastily put on), to being untucked (as it should be) quite a few times.
Continuity mistake: After Rory is walking with Dean, it goes to a shot of Rory and Lorelai eating at Luke's Diner from outside. Rory is wearing a light blue sweater and Lorelai has a black shirt on. Then it goes inside the diner and Rory is wearing a dark bluish/grey sweater and Lorelai is wearing a purple shirt. The first exterior shot is used from the very last scene of the episode. (00:27:05)
Other mistake: Rory asks Emily for baby pictures of Lorelai, but Emily says Lorelai burned them all because she had such a big head when she was little. But in "Love and War and Snow" earlier in the season, Emily, Richard and Rory looked at a baby picture of Lorelai in a bunch of petticoats the night Rory stayed over with her grandparents during a snowstorm.
Visible crew/equipment: When Rory is finally going back to Yale, in the scene where she and Lorelai are standing by the car debating who Paul Anka likes better, Rory gets in the car to drive away, but in the next shot of the car actually driving away, you can see what is a man's arm driving the car. (00:06:50)
Continuity mistake: Lorelai and Sookie take some containers out of the car and head towards Emily and Richard's door. When you see the next shot of them at the door, the containers Sookie is carrying are different from the ones she took out of the car, without her rearranging them.
The Incredible Sinking Lorelais - S4-E14
Continuity mistake: Dean calls Rory, and towards the end of the conversation mentions getting his first cell phone. This is false. He's had a cell phone the whole series. Paris even calls it in the season 2 episode "Can't Get Started" when Rory and Dean are at Sookie's wedding.
Continuity mistake: In S1E3 "Kill Me Now" when Babette tells Lorelai that Cinnamon is stuck under the porch again, she refers to Cinnamon as "him", but in this episode Babette talks about Cinnamon being female.
Continuity mistake: When Lorelai and Max are on the porch talking about whether or not Max can go in, there are a few snowflakes on Lorelai's hat which disappear and reappear while they're talking.
Double Date - S1-E12
Factual error: Lane wants Rory to talk to Dean about setting up Lane with his friend Todd. While asking Rory to do this, Lane asks for the date to be planned for the following Sunday, after church; however, Lane is Seventh-day Adventist and they believe the Sabbath is Saturday and therefore attend church on Saturday, not Sunday. (00:04:45)
Suggested correction: Many Seventh-Day Adventist churches do actually hold church on Sunday.
Kill Me Now - S1-E3
Audio problem: When Lorelai and Rory are sitting at a table, with Rory looking at herself in a mirror, they talk about Rory's hair. Right after this, Rory asks, "do you want something to drink?" Her mouth doesn't move at all. (00:30:00)
The Lorelais' First Day at Chilton - S1-E2
Continuity mistake: Luke uses a red screwdriver trying to get something out of the toaster and leaves the screwdriver in the toaster while he goes to get coffee. When it cuts back to Lorelai, the screwdriver is on the counter, beside the toaster. (00:18:20)
Fight Face - S6-E2
Other mistake: While in Luke's diner, Luke hands Lorelai a cup of coffee in a 'to go' cup. When Luke puts the coffee in front of Lorelai, the cup makes a hollow sound when it hits the counter, obviously indicating that there's no actual coffee in the cup.
The Big One - S3-E16
Continuity mistake: In 1.06 - "Rory's Birthday Parties" Paris says "Ten generations of Gellers have gone to Harvard". In this episode Paris says "Five generations of Gellers have gotten into Harvard"
Visible crew/equipment: When Jess shows up at Principal Merton's office because he couldn't get prom tickets, as Jess shuts the office door the hand of a crew member is visible between the door and frame, slowing the moving door. (00:14:30)
Other mistake: The Warner Bros. Studio Tour building is quite a distinctive high-rise, and it's located at the corner of Avon and Warner Blvd across the street from the Warner Bros. Studio backlot, which includes the location set of Stars Hollow town square. During the series, in a few episodes such as "Will You Be My Lorelai Gilmore," that high-rise building can be seen from the town square, past Doose's Market, directly behind Sophie's Music store.
The Fundamental Things Apply - S4-E5
Continuity mistake: When Rory comes into the room to answer the phone and sees Paris avoiding the call because it's her boyfriend Jamie, she empties the contents of her school bag onto the desk, including her mobile phone. Then later in the scene when Rory suggests Paris use her mobile phone to call Jamie, she pulls it out of her bag again, despite having left it on the table all but half a minute earlier.
New and Improved Lorelai - S6-E1
Continuity mistake: When Lorelai and Luke are in bed talking about having kids, the first time Luke lies down he is on a blue striped pillow, but the second time it is a light brown pillow.
Continuity mistake: During the town meeting, when Harry is talking about the Battle of Stars Hollow, in the shots facing Harry his hat is sitting on the top edge of the lectern, but in the shots from over Harry's shoulder the hat is sitting on the lectern's inner shelf. (00:01:15)
Suggested correction: That's exactly the point of the scene. Kirk knew that her name was "Miss Patty" but he didn't know she was THE "Miss Patty" about whom everyone was speaking.
They also refer multiple times to Kirk growing up in Stars Hollow. He would have known. In Stars Hollow, there couldn't ever be another "Miss Patty." That's just not how they roll.