The One With The Truth About London - S7-E16
Continuity mistake: At the beginning when Chandler is talking about two reasons to pick a minister, he counts them using his left hand. However, in the wide shot straight afterward his right hand has two fingers up and his left hand is in his lap. (00:02:00)
The One Where They All Turn Thirty - S7-E14
Continuity mistake: In one of Monica's flashbacks, her hands move between shots with no time to do so. (00:10:50)
The One With Monica's Thunder - S7-E1
Continuity mistake: When Phoebe is singing for the first time, the door behind her is open or closed, depending on the shot. (00:05:00)
The One Where They All Turn Thirty - S7-E14
Continuity mistake: In the shot of Tag giving Rachel a scooter, her shirt is fine. The next shot of Rachel, she has a bow from the present on her shirt. The next shot is of Chandler, then next shot of Rachel the bow is gone again. (00:11:55 - 00:12:25)
The One With The Truth About London - S7-E16
Continuity mistake: When Joey is reading his speech about all the giving and receiving, Chandler has his legs on the table at the coffee shop. You can see his shoes on the table when they show Joey, but when they change the shot to Chandler his legs are on the floor and crossed. (00:10:55)
The One With The Truth About London - S7-E16
Continuity mistake: In the flashback, Chandler says to Joey that he is watching a movie when the camera cuts to show the blank screen. In the reflection, you can see that there is no-one present in the room. (00:18:20)
The One With Monica and Chandler's Wedding, Part 2 - S7-E24
Continuity mistake: During an earlier episode Monica gave up her dream wedding dress so Chandler could have The Swing Kings at their wedding. So it is a little surprising that the band they actually have are called Jungle Swing.
The One Where They're Up All Night - S7-E12
Factual error: In the opening scene, Ross remarks on the stars the group is gazing at. In reality, there would be far too much light pollution in this part of New York City to be able to see any celestial bodies such as comets or stars.
The One With Monica's Thunder - S7-E1
Continuity mistake: When Joey is asking how old he looks, his hands are in his pockets. In the next shot he is gesturing, then instantly his hands are back in his pockets. (00:09:00)
The One With Ross's Library Book - S7-E7
Continuity mistake: At the very beginning, Joey is eating some cereal and then says he has to go to work, so puts it down on the table - but in the rest of the scene it vanishes. (00:00:15)
The One With Joey's Award - S7-E18
Continuity mistake: When Rachel and Joey are talking, the syrup bottle moves from the label facing Rachel to the label facing the camera. (00:05:50)
The One With The Nap Partners - S7-E6
Continuity mistake: Monica and Chandler are in their apartment talking about Monica's worries that Chandler would dump her if she put on weight. When we first see Monica, the bite mark in her apple is quite small, but a few seconds later, it is suddenly much bigger without her eating any more of it. (00:18:00)
The One Where They All Turn Thirty - S7-E14
Continuity mistake: When Monica is at the party and she is drunk, there is one point when she is sitting down on a chair with Chandler on her right. Chandler is holding her left hand (which has a snack in it), but when it cuts to a front view of Monica, suddenly both her hands are on her lap. (00:13:45)
The One With Joey's New Brain - S7-E15
Continuity mistake: When Joey is talking to the woman whose brain he receives, as the shot changes she is holding a glass, then a cigarette then a glass again, with no time to change objects, let alone anywhere to put the other. (00:06:05)
The One Where Chandler Doesn't Like Dogs - S7-E8
Revealing mistake: While Monica is sneaking the dog back to her apartment and Chandler is in the toilet, as Monica lifts her hand to her mouth she whispers, "Up!" to get the dog to stick its head out of the handbag. (00:15:00)
The One With Chandler's Dad - S7-E22
Continuity mistake: When Monica receives her gift from his father, the Porsche, it's gray. When Rachel takes the keys from Ross' jacket and gets into the car in this episode, the Porsche is black. (00:04:49)
The One With The Truth About London - S7-E16
Continuity mistake: In the flashback scene where Chandler and Monica are in the hotel room, there are three paintings on the wall of flowers, etc. In the original scene from ‘the one with Ross' wedding part 2' the pictures are completely different.
The One With Rachel's Book - S7-E2
Audio problem: Chandler, Monica and her parents are at dinner to discuss the upcoming wedding. When they describe how they remodeled the kitchen when she broke up with Richard, the camera pans to Monica and her mouth is moving but there's no sound. It then switches camera angles and Monica audibly asks, "Well what about when I started dating Chandler?" Which is what she said in the frame before with no sound. (00:11:00)
The One With Ross's Library Book - S7-E7
Audio problem: When Janice is groaning about Clarke sanding her up, the second "Oh" is obviously pre-recorded and the third "Ah I j..." is audio from the next closeup shot that hasn't been cut to yet. On top of this, her mouth moves on neither of them. (00:12:15)
The One With The Cheap Wedding Dress - S7-E17
Continuity mistake: Chandler's chair appears in this episode again, although it was broken in 7/13 and thrown out. It is not in the room in 7/14-16, but in 7/17 it's there again, then it is gone again in 7/18.
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.