Other mistake: When Christopher shows up, he says "tomorrow is Saturday." Wouldn't the girls be at Friday night dinner? Not ordering pizza?
Other mistake: When Rory is dropped off in the morning after spending the night with her grandparents, she walks from the car to the porch where Lorelai is standing, but even though it's snowing there aren't any snowflakes anywhere on Rory. (00:39:10)
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.
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.
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.
Other mistake: In the opening scene, Lorelai and Sookie go to the bakery to pick up a cake. Lorelai pays for the cake but they leave the bakery empty-handed.
Double Date - S1-E12
Other mistake: When Rory and Lane get caught at the movies, Lorelai said she will not lie to Mrs. Kim because she has to respect that Mrs. Kim doesn't want Lane to do something. In reality, Lane is allowed to do things Mrs. Kim would not approve of all the time i.e. Listening to ungodly music, eating pizza, wearing different clothes.
Other mistake: When Lorelai asks her mother which veil she should choose for her upcoming wedding to Max, Emily responds that her head is too big for a veil, and she could consider a tiara. When Lorelai responds quizzically with 'umm a tiara?' Emily says 'that's what I wore'. However, in s1e8, the photo album Rory looks through with her Grandparents features a picture of Emily and Richard that Emily calls their 'wedding photo' (in which she is pictured wearing a veil, not a tiara). (00:43:15)
Other mistake: After Lane goes home, when Rory watches her mom talking to Max note the short window over the kitchen sink behind Rory (not the tall window on the same wall). In the next shot, from outside that short window, we see Rory pull the photo strip out of her pocket then proceed to walk to that window and stand directly in front of it. The problem is there should be a sink and cabinets under that window blocking Rory from standing beside the window. (00:43:05)
Other mistake: While Luke and Lorelai are talking about Rachel in the storage room, after Lorelai places some jars on the shelf, the jars on the shelf behind Lorelai turn, change position or vanish, between shots.
Richard in Stars Hollow - S2-E12
Other mistake: Paris was looking to find the seedy side of Stars Hollow. Inside of Luke's she hid behind a menu commenting that she wanted to blend in. She then asked Luke if he gets a lot of truckers. We have all seen the exterior of Luke's and the town square. Paris has walked through it. Where, would a big rig possibly fit or park? Paris is extremely intelligent. She would not have asked the question. Doing so was totally out of character.
Presenting Lorelai Gilmore - S2-E6
Other mistake: Dean leaves the house the night before the debutante ball. He says goodbye and leaves the room but he never leaves the house. He never is seen going into the foyer and the door doesn't close.
Twenty-One Is the Loneliest Number - S6-E7
Other mistake: Though I love the 21st birthday at the casino plan, it's flawed. Rory will not be able to play blackjack until she is 21. She can't be playing when she turns 21. Casinos, to the best of my knowledge, won't let you on the gaming floor unless you are 21. She has to turn 21 first.
The Big One - S3-E16
Other mistake: Headmaster Charleston called Rory to discuss the speech contest. His secretary conferenced in Paris. When Headmaster Charleston hung up, the connection between Rory and Paris should have been severed. They were both connected to him, not to each other.
Twenty-One Is the Loneliest Number - S6-E7
Other mistake: After Emily goes to the pool house on the pretence of looking for a blouse, she asks Logan about plans for Rory's birthday. Later, Emily and Richard talk. Emily suspects that Rory is ready to have relations with Logan. She says that she caught them getting cozy on the couch. Emily didn't catch them doing anything. There was no way for Emily to see inside. Both Logan and Rory got off the sofa to answer the door. Emily didn't see anything. And, Logan told Emily that he had no plans for where his birthday. He knows that Emily is planning a party, yet he offered to take Rory away for her birthday. Emily would've been devastated.
Other mistake: Lorelai is in bed post breakup. Rory returns from running errands for her. She comes upstairs with Frank who is carrying the television. Frank puts down the television and leaves. When Rory leaves, Lorelei turns on the TV. No one plugged it in or hooked up the cable, assuming that cable is installed in her bedroom (which is extremely doubtful). Lorelai would not have been able to flip through channels as she did.
Women of Questionable Morals - S5-E11
Other mistake: When Rory goes to see her father after Strobe dies, she brings a paper bag with cookies. Christopher comments "and milk", even though the bag was creased. He couldn't see into the bag because the bag is closed.
Other mistake: Lorelei, Rory, and Luke are about to leave for Emily and Richard's wedding. Babette is on the sofa half passed out from the bachelorette party. When she hears Lorelei speak her name her head pops up to say goodbye, and she also comments that Luke looks nice. Luke is wearing a long overcoat. She could not possibly see how he looks, plus she was viewing him from behind.
Chosen answer: Lorelai and Christopher get married impulsively in Paris but they get divorced shortly after returning home. I don't know the exact number of days or weeks but they definitely weren't married for more than a couple of months.