The Prodigal Daughter Returns - S6-E9
Continuity mistake: April is in the diner taking a hair sample from Luke and takes his photo. She puts the camera in her pocket and in the next shot she has the camera in her hand again.
The Prodigal Daughter Returns - S6-E9
Continuity mistake: At the beginning of the episode, Lorelai can't get in the front door because Luke has installed a chain lock. Near the end of the episode, when Rory returns home and Lorelai rushes out the front door, there is no chain lock present on the door.
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.