Other mistake: In 'The One with the Ick Factor' (Season One) Monica states that she is 26 years old. This episode takes place in 1994/95. However there are numerous other episodes such as 'The One With All The Thanksgivings' that show Monica and Rachel (who are the same age and in the same class) still being in High School in 1988. In 'The One Where The Stripper Cries' the two have to sneak into a college party in 1987 as they are still high school age. They should be at least 19 or 20 in 1987/88.
Other mistake: In his apartment from later episodes, Ross' kitchen door is on the same wall as the front door, and it is a long and narrow kitchen, but Ross' apartment is between two others. The floor plan doesn't make sense unless the kitchen is only a foot wide, otherwise it would jut off into the hallway.
Other mistake: In almost every season when the friends are in the coffee shop, it shows a front view of Central Perk; and a lot of times, in different episodes, the same (unaging) lady with blonde curly hair is walking past the shop. There are also a couple of different episodes where two babies with red hair are being carried past the coffee shop.
Other mistake: In the first shot of Central Perk in "The One with the Monkey" and "The One with the Dozen Lasagnas", the same footage has been used twice because the same three people are having the same conversation in both episodes.
The One Where Monica Gets a Roommate - S1-E1
Other mistake: When Rachel arrives at Central Perk, Monica introduces her to everybody, including to Chandler, as if they don't know each other. In later episodes, we learn that Chandler met Monica and Rachel a couple of times when they were in high school (including when Monica cut his toe off). Chandler even kissed Rachel once, and since Chandler always says that he hasn't kissed many women, he should have perfectly remembered Rachel, and Monica should have remembered that the two of them knew each other. (00:04:40)
Suggested correction: Chandler and Rachel never really knew each other well. Chandler will have been in her mind as that guy that her best friend's brother hangs out with, and Chandler will only know her as the friend of his friend's sister. I doubt they'd remember each other as the kiss they shared was when she was drunk, and they didn't see each other for 6 years while Rachel lived a richer and dependent on her father type life.
The One Where Monica Gets a Roommate - S1-E1
Other mistake: At the end when Ross and Rachel split an Oreo, you can see that Rachel is holding 2 parts and Ross somehow still has one. (00:20:38)
The One Where Monica Gets a Roommate - S1-E1
Other mistake: Ross is a paleontologist but is seen working with the display on early humans which would be more of a job for an anthropologist.
The One with the Sonogram at the End - S1-E2
Other mistake: At the beginning when you see outside the museum, there's a man in a red t-shirt looking at the camera. (00:01:50)
Other mistake: When Joey announces that he has a job in the new Al Pacino movie, Ross is holding a bottle of peach Snapple with part of its brand name whited out, so it reads "S pple" on the label. (00:13:50)
The One with the Blackout - S1-E7
Other mistake: Ross says that he was at Disneyland with Carol and got caught hooking up on Small World and asked to "never to return to the Magic Kingdom." Disneyland is in California and the Magic Kingdom is part of Disney World in Florida. (00:06:10)
The One with the Blackout - S1-E7
Other mistake: Phoebe says she was last to know Monica had a crush on Joey when he moved in and Joey acts as though he never knew this. However, when we see him moving in a later episode, he knows Monica has a crush on him, and he is under the impression that Monica wants sex and so strips off in the living room while Monica is preparing some drinks for the pair. (00:13:10)
Suggested correction: I may understand the situation but please do correct me if I'm wrong. Basically in the flashback episode they saw each other in the hallway and smiled at each other. They would've both got the impression that the other one liked them. However, after the lemonade incident he would have then got the impression that he was wrong and Monica didn't actually like him. Finally, Joey heard that she did like him and got a bit confused and a bit happy at the same time.
The One with the Blackout - S1-E7
Other mistake: When Ross and Rachel are out on the balcony alone for the first time, there are no lights on in NYC apart from candle lights. Look in the BBQ behind them though to see a very bright and very white light reflected in the paintwork. (00:13:50)
The One Where Nana Dies Twice - S1-E8
Other mistake: When Ross is helping choose a dress and shoes for Nana to wear, he is behind the chest of drawers in the cupboard. He looks in a shoebox and finds lots of pink sweet'n low packets, then pulls down another box and lots of packets fall down on him. However, it is obvious that someone is above him showering the packets down, as they are coming from directly above him, not from on top of the door. (00:12:35)
The One with the Dozen Lasagnas - S1-E12
Other mistake: After Carol asks Ross if the lasagna is vegetarian, the camera briefly goes out of focus before Ross says "I'm pretty sure that it is." (00:05:00)
The One with the Dozen Lasagnas - S1-E12
Other mistake: At the end, Monica is playing as red, but we see the blue team score on the foosball table. However, Monica states that she scored and beat Joey and Chandler again. A previous correction says to look closely as the red team scores, That correction is completely invalid as the player in goal is red. Why would Monica score in her own goal? And Also the blue players can be seen to spin. (00:22:10)
The One with the Stoned Guy - S1-E15
Other mistake: Mid episode when Monica turns off the cordless phone after being told by Wendy that she can not make it, the phone makes the "out of range" audio tone instead of the "power off" audio tone. Occurs directly as Monica says, "Wendy, we had a deal, yeah, you promised. Wendy, Wendy, Wendy.".
The One with Two Parts: Part 1 - S1-E16
Other mistake: When the woman in blue walks into Chandler's office, the camera pans back a bit too far showing the edge of the set. (00:05:20)
The One with Two Parts: Part 2 - S1-E17
Other mistake: Rachel is limping in the hospital for the first time. When she gets back home, she walks perfectly fine. Then in the hospital, she starts to limp again.
The One with All the Poker - S1-E18
Other mistake: During the third game of poker, the bottle of raspberry Snapple on the table has part of its brand name whited out on the label.
The One Where the Monkey Gets Away - S1-E19
Other mistake: When Rachel's watching the soap opera on TV while babysitting Marcel, she and Marcel are sitting in the middle of the couch, but in the closeup of Dr. Francis we can see the reflection of the empty couch at the bottom of the TV screen.
