The Kids Are Alright (1) - S6-E1
Continuity mistake: During the beginning intro monologue, Jen is shown seated between her parents on a couch. The two actors portraying her parents are only shown from the back, but they appear to be different people than the original actors who portrayed them. The father, especially has different hair and wears glasses. (00:01:40)
...Must Come to an End (2) - S6-E24
Audio problem: During the narrative for the Season Finale, second half, Paul Stupin the Executive Producer is talking about Joey and Pacey's romance in the show. He mentions that they went on an "epic journey on a sailboat all over the world." He's a bit mistaken; as when Joey and Pacey went sailing at the end of Season 3, they sailed from Massachussetts down the Eastern Coast to Florida and back again. It was hardly "all over the world". (01:04:45)
Revealing mistake: When Pacey and Rich are physically fighting in the office, there is a quick shot of a person who is supposed to be Pacey leaning forward over Rich and hitting him. However, if you look closely you can see that the hair on this person although dark brown, appears much longer and curlier than Pacey's current hairstyle. Also-just before that shot ends, you can see the longer hair swing away from his neck loosely on the right side. The next shot of Pacey shows his shorter haircut, so I believe the longer hair was actually a stunt man substituting for Pacey in a risky, physical scene. (00:40:00)
All Good Things... (1) - S6-E23
Plot hole: When Jen and Jack are talking at the B&B, he picks up the bottle of pills from Jen's purse and asks her about them. She lies, telling him they are pills for Grams when in reality they are Jen's medication. But Jack is examining the label closely, and wouldn't he see pretty easily that Jen's name was listed instead of Grams? He had plenty of time to read the entire label. (00:28:40)
...Must Come to an End (2) - S6-E24
Audio problem: During the Season Finale Narrative, second half- Creator Kevin Williamson mentions that The Kiss between Doug and Jack on the beach was "the second gay kiss in the show". He's a bit mistaken, as this was actually the 4th gay kiss in the entire series. Jack kissed Ethan in Season 3, Toby in Season 4, David in Season 6, and Doug in the Season Finale. (01:36:00)
That Was Then (aka Before and After) - S6-E16
Revealing mistake: In the very beginning of the episode, Pacey is watching TV and gets up to look out the window towards Hell's Kitchen. As he moves back from the window, he accidently bumps the kitchen counter/cabinets. An entire section of 'counter/cabinet' moves noticeably; revealing it to be a cheap, flimsily-built fake kitchen counter/cabinet instead of a more substantial, real one. This was obviously just part of a set.
Continuity mistake: At the beginning, Pacey and Joey are dining at a large table while Pacey is flirting with the woman on his right. Joey goes underneath the table to retrieve her shoe, and sees what is apparently the woman's left hand on Pacey's knee. But the very next shot of the woman above the table shows her right hand up against her face, and her left arm folded, hand on the table. Her left arm doesn't appear to have moved, and there was no time for a transition from Pacey's knee to above the table. (00:00:55)
Audio problem: When Jen is talking to Jack at the Helpline Office, she jokingly tells him that he is too young to be likely to "haunt them with your sad, single self." She appears to fumble her dialogue, however, and you can hear her almost switch the words around and say "single, sad self." She catches herself, and says 'sad' first instead. (00:35:50)
All Good Things... (1) - S6-E23
Plot hole: Dawson is in his bedroom, and hears a noise outside his window. He panics, and picks up his laptop to use as a 'weapon' if necessary, while approaching the window. This doesn't seem logical; because for one thing he knows Joey is in town and she has been coming in through that window for years, and wouldn't he think of that first? Also-highly unlikely Dawson would actually use a very expensive Apple laptop as a weapon when it could be damaged, and he relies on it extensively for his work as a Writer/Producer. (00:30:55)
All Good Things... (1) - S6-E23
Continuity mistake: When Jack is pulled over near the start the creek behind him is empty, and remains like that throughout the scene. Then for the last few shots before he drives off again a sailboat has appeared in the background, literally out of nowhere. (00:06:45)
The Importance of Not Being Too Earnest - S6-E3
Other mistake: In the scene where Pacey and his Boss are out to lunch, his boss states that he just bought a car, so they head to a dealership. When they are walking in, his boss goes to a car that's kept in the showroom and dusts it off with a cloth as though that's the one he bought, since it is unlikely that he'd clean off a car that wasn't his. A car that someone just bought would not be kept in a showroom; it would be on the lot and ready to go, especially if the paperwork was already completed, as the boss stated when he said it was already signed and paid for.
Lovelines (aka The Eddie) - S6-E19
Character mistake: In the scene when Dr. Drew has Joey and Eddie on stage, they are arguing and Joey says that Eddie moved away and dumped her twice. Actually, he only dumped her once, when he moved out of his apartment and back home with his parents. The 2nd time that Joey is referring to is when Eddie moved to California for the writing workshop, which SHE helped and encouraged him to do. So he did not dump her 2 times; she basically pushed for him to leave the 2nd time, yet she acts as though this situation never occurred.
Answer: It's only explained once in the series. Jack says to Andie "I tried to start kindergarten without you", meaning Andie was smart enough to start school early.