The One Where Rachel is Late - S8-E22
Continuity mistake: At the end, when Rachel and Ross leave for the hospital, Rachel grabs the keys. In the close-up, when Rachel asks, "Do you think we have time?" she holds the keys up in her left hand while Ross holds her empty right hand. It then cuts to a medium shot, and the keys are now in Rachel's right hand, the same hand Ross holds. (00:20:40)
The One With The Red Sweater - S8-E2
Continuity mistake: Monica is sitting in the living room with all her wedding presents, waiting for Chandler to return. She begins to open a large parcel and reveals a brown cardboard box. Then the camera moves to Joey, and when it moves back, the parcel is wrapped up again. This happens about three times. (00:05:05)
The One Where Rachel Tells... - S8-E3
Continuity mistake: While Joey's on the phone with Monica telling her the phony story that he and Phoebe smell gas coming from her apartment, on the table are the glass casserole dish and lid from the chicken parmigiana and a water bottle, but in the closeup there's only a ceramic blue bowl filled with eggplants and squash, and it keeps switching in the following shots,.
The One With The Halloween Party - S8-E6
Continuity mistake: When Phoebe is talking to Ursula's fiance Eric, he is wiping sweat off his face with a napkin. He puts the napkin to his eye and then in the next shot it changes to the other eye without him having enough time to change it. This happens again when at one point he's wiping his eye and then suddenly his forehead. (00:07:45)
The One With Rachel's Date - S8-E5
Continuity mistake: When Monica and Phoebe both confront Tim, they blurt out their news at the same time. In the three-shot he uncrosses his arms in surprise, but in the shot of Phoebe we can see he's still got his arms crossed. (00:17:00)
The One With The Tea Leaves - S8-E17
Continuity mistake: When Ross opens Mona's door with the hidden key he only has to unsnap the door. Also, when Mona enters her flat a moment later she has to unlock the door. (00:10:50)
The One With Monica's Boots - S8-E10
Continuity mistake: In The One With Monica's Boots, Monica is removing her trainers and replacing them with her boots so it looks as if she was wearing her boots all along. In one shot her left jean leg is tucked into her boots, but when she stands up it is sitting perfectly. (00:07:25)
The One With The Rumor - S8-E9
Continuity mistake: When Ross hands Rachel the Yams in order to break the tension, the amount of food on both Ross' and Will's plates changes between shots. Also several wine glasses appear on the table. (00:12:30)
The One Where Joey Tells Rachel - S8-E16
Continuity mistake: At the end of the previous episode, Joey tells Ross that he has feelings for Rachel just as Ross is about to walk out of Central Perk, and there's a vase of tulips on the table beside the door and two things hanging on the coat hooks. The opening scene of this episode continues at the same moment of Joey's admission, and the vase has vanished and there's only a sweater hanging on the coat hooks.
The One Where Joey Tells Rachel - S8-E16
Continuity mistake: When Monica and Chandler get back to the apartment Chandler tosses his coat over the back of the couch, and while they're talking about soulmates and a house of cheese we can see Chandler's coat in the reflection on the TV, but then it vanishes in the reflection, though it reappears when Chandler says that he wants to take Monica out to a restaurant.
The One Where Rachel Tells... - S8-E3
Continuity mistake: When Rachel sits down in Ross' apartment, she places her magazine down on the table with its binder facing the audience, but while Ross goes on about their one night just being fun the binder is now facing the opposite way on the table, and then it's flipped back to the original position.
Continuity mistake: When Ross introduces himself to Mona, the reception place card that Mona's holding switches from her left hand to her right hand, between shots.
The One With The Video Tape - S8-E4
Continuity mistake: When Ross turns on the camera and sits down in front of it, "flirting" with it and drinking wine, what you can see on the little camera screen is very different from when they play the same clip on the TV, in which looks like he was sitting much closer to the camera then he actually was.
The One With Ross' Step Forward - S8-E11
Continuity mistake: When Phoebe is getting drinks out of the refrigerator, she gets out two different type bottles, and they switch hands during the scene. (00:17:50)
The One With The Rumor - S8-E9
Continuity mistake: The gang confronts Ross over his affair with a fifty-year old librarian when he was younger. If you watch the mirror behind him (in one of the girls' rooms), it changes angles every time the camera cuts between Ross and the rest of the gang. (00:17:40)
The One With The Rumor - S8-E9
Continuity mistake: Right near the end of the episode when Joey comes in wearing the maternity pants, he pulls out the chair from the table twice. (00:21:20)
The One With The Video Tape - S8-E4
Continuity mistake: When Ross walks into Joey's apartment after everyone watched the tape, you see him come in and they cut to Rachel and you hear a door close, they cut back to Ross and the door is still open and he shuts it again. (00:20:00)
The One With The Stripper - S8-E8
Continuity mistake: When the stripper has just entered the apartment you can see her putting down her right arm twice, without enough time in between to put it back up. (00:09:50)
The One Where Rachel Has a Baby, part 1 - S8-E23
Continuity mistake: When the couple who has bad pet names for each other is sharing the maternity room with Rachel, the man is unpacking a suitcase that he closes, but in the next shot its open and he flips the top closed again. (00:09:10)
The One With The Video Tape - S8-E4
Continuity mistake: When we see the video, notice Rachel's hair. It is the same length as it is throughout season 8, but her hair is supposed to be the short bob she had in season 7 since it took place then. (00:17:00)
Answer: Usually by the seventh night of Hanukkah you don't know what to get the other person, and you will probably resort to getting the other person something insignificant. Chandler is basically saying that the pen is a stupid gift.