The Big One - S3-E16
Visible crew/equipment: At Chilton, after the teacher returns the graded papers to the students, when she walks to the front of the class her T-mark is visible on the floor. (00:04:55)
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"
The Big One - S3-E16
Visible crew/equipment: When Lorelai and Rory are at Richard's while Emily is away visiting her friends, Richard steps out to answer a call. When Richard returns we can see a blue T-mark taped to the floor behind Rory's side of the sofa. This T-mark is visible again when Richard asks about Rory's speech, because he'd like to be there. (00:20:00)
The Big One - S3-E16
Continuity mistake: When Lorelai sits down on the porch swing at Suki's house to talk, they are both sitting right next to each other, sharing the same blanket. During their conversation, when the shots face each of them individually, you can see there is an empty space beside them on the swing, with both sides of the swing's chains visible. (00:20:50)
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.
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.