Factual error: When Rory drives up the road, in the shot from inside the car there's a stop sign facing her up ahead to her right, but in the next shot that stop sign is now facing the opposite way, which has the wrong side facing the driver.
Rory's Dance - S1-E9
Factual error: The morning after Dean and Rory fall asleep at Miss Patty's, when Patty wakes them up, she tells them it's five-thirty in the morning. When Rory runs out into the street, there is snow on the ground and the sun is up. In Connecticut, there is no time of year in which there would be both snow on the ground and sunlight at 5:30 a.m. (It's not streetlights either - in other episodes that take place at night in the town square, the streetlights do not light up the entire square - they are some distance apart, and their light is concentrated around the poles).
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.