The One With the Holiday Armadillo - S7-E10
Continuity mistake: During this episode, Chandler is having major problems slipping people dollar bills. He asks Monica if Richard (her ex) use to slip people notes. But in Series 2 there was an episode where Chandler and Joey were doing impressions of Richard; they impersonate him by slipping money to each other with no problems. So not only has Chandler forgotten that Richard used to slip money, he's also lost the ability to slip money himself. (00:05:05)
The One With Rachel's Book - S7-E2
Continuity mistake: Chandler and Monica are having dinner with her parents. He asks Jack how he and Judy got engaged. He starts, "Well I'd gotten Judy pregnant..." Then they talk about how Jack told Monica's friends a "scary story" about how Judy got pregnant because her method of birth control, her diaphragm, had malfunctioned (damaged by a dog). In the rest of the show, however, we are continually hearing that the firstborn, Ross, was "a medical marvel" and that they thought Judy was barren. This apparently is the main reason why they love Ross more than Monica.
The One Where Chandler Doesn't Like Dogs - S7-E8
Continuity mistake: In this episode, it is stated that Ross does not like ice cream because it's too cold. However, back in The One Where Ross Dates a Student, you can see Ross on a date with Elizabeth eating an ice cream.
The One With The Cheap Wedding Dress - S7-E17
Continuity mistake: Monica chooses a wedding dress at an expensive boutique, then later goes to a discount store to buy the same style dress at a half-off sale. The dress she buys is different from the one in the boutique, having wider and frillier straps. When she tries it on later at the apartment, it is now the same style as the one at the boutique. (00:04:00 - 00:07:15)
The One With Monica's Thunder - S7-E1
Continuity mistake: The beginning to series 7 takes place right after series 6 ended, basically Chandler has only just proposed to Monica. Yet Monica's hair is visibly different; at the end of series 6 she had no fringe and a center parting, now she has a fringe. Also Chandler, is visibly thinner, with a gaunt face due to losing 20 lbs in between the two series. Rachel also has had a hair cut, her long extensions have been removed and she is back to her usual hair length.
The One Where They All Turn Thirty - S7-E14
Continuity mistake: Rachel is said to be the youngest in the group as they reminisce about their 30th birthdays, however this episode reveals that almost all of the characters ages have been inconsistent throughout the series. In Season 1, Joey is said to be 25. In Season 2, he says he is 28. In S7 E1, he says he is 31. In Season 1, Monica is said to be 26. In Season 7, she should therefore be at least 32. Rachel graduated high school with Monica, so she should also be about 32 in S7, not just turning 30. She would have been 26 in S1. But, in Season 4, she refers to herself as a "28-year-old cheerleader". Based on Season 1, Joey should actually be the youngest member of the group, not Rachel.
The One With Joey's New Brain - S7-E15
Continuity mistake: When Rachel appears when Joey has the actor in his appartment, the door is closed. When she goes to get Monica, the door is open. (00:21:30)
The One With Rachel's Book - S7-E2
Continuity mistake: When helmet-wearing Vicar Joey taunts Rachel one too many times she turns the tables on him, so when Joey backs away from Rachel he gets pushed up against the front door, and although he can't move, in the shot facing Joey he's at the left side of the door, but in the side shots he's at the right side of the door.
The One With Joey's Award - S7-E18
Continuity mistake: When taking Jessica's award, Rachel opens the door. But when the camera cuts, Joey is first through the door. (00:18:40)
The One With The Truth About London - S7-E16
Continuity mistake: In the flashback to London, the dress Monica is wearing is not the same one that she is wearing in the original episode, The One with Ross' Wedding, although one can see that they tried to make it look similar. (00:16:20)
The One With All The Candy - S7-E9
Continuity mistake: When Ross is trying to convince Phoebe to try to learn to ride her bike again, the bike is completely covered by a large white sheet in the corner of Phoebe's room; however, in a later shot, the wheel of the bike is visible. (00:13:15)
The One With Chandler's Dad - S7-E22
Continuity mistake: When Ross and Rachel are out in the Porsche it is dark outside, but when it later cuts back to Joey in his apartment stealing Rachel's underwear it is broad daylight. It is also light outside when Joey and Phoebe are talking at the coffee house later on. (00:10:30)
The One With Phoebe's Cookies - S7-E3
Continuity mistake: While trying out different recipes, at one point Monica's holding a cookie in her hand. It's a whole cookie, but when the angle changes, suddenly a chunk is missing. (00:13:00)
The One With Joey's Award - S7-E18
Continuity mistake: When Joey sets down the award he sets it at a straight angle to the counter edge, but when Joey catches Rachel about to pick it up it is angled and not straight. (00:13:45)
The One Where Rosita Dies - S7-E13
Continuity mistake: In this episode we seemingly understand why Ross and Monica's parents favor Ross. In one scene at Monica's apartment Ross says that it is because their parents thought Judy was barren. This would make sense except that in TOW Rachel's Book, Jack and Judy tell Monica and Chandler that they had to get married because Judy was pregnant. Judy was using a diaphragm as birth control and Jack's dog ate it. It doesn't make sense that Judy would use a diaphragm if she thought she was barren. This was not news to Monica since she said she had heard the story about the dog eating her mother's diaphragm at her 5th grade Halloween party. (00:04:15)
The One With All The Cheesecakes - S7-E11
Continuity mistake: Chandler walks into his apartment to find Rachel eating cheesecake without him. As the door is shutting, the pen on the Magnadoodle is hanging loose; it can be heard hitting the door when Chandler is closing it. The next shot shows Rachel stop eating, and when we next see Chandler, the door is closed and the pen is in its holder. (00:15:50)
The One With Rachel's Assistant - S7-E4
Continuity mistake: In the scene when Joey is talking to the producers of Mac and Cheese, he says, "We're not even shooting them anymore?!" As he says this he lifts his left arm up, but in the very next shot his left arm is back down by his side. (00:14:40)
The One With All The Candy - S7-E9
Continuity mistake: When Phoebe sits on the swing (when learning to ride her bike), her scarf has one end down her front and the other over her left shoulder. In the next shot, the end is over her right shoulder instead of her left. A couple of shots later, it is switched back again. (00:11:05)
The One With All The Cheesecakes - S7-E11
Continuity mistake: Phoebe and David see each other at the coffee house and start talking. The buttons on Phoebe's red cardigan go from gaping to properly shut a number of times throughout the scene. (00:09:30)
The One Where They All Turn Thirty - S7-E14
Continuity mistake: Rachel's birthday has always been in May, not February/March. (00:16:00)
Answer: The painting doesn't have a name, and if it does it is never mentioned in this episode.