The One Where Paul's The Man - S6-E22
Continuity mistake: When Monica is listening to the answering machine, the bread in the blue and white bag behind her changes position. (00:12:40)
Factual error: This mistake is from series 6 onwards, with Ross' new apartment: There is an impossibility with Ross' kitchen, but not all of the time. It depends on the layout of the hallway outside his apartment. If the hallway continues along for a bit before going left or right, then the kitchen should stick out. However, when the hallway is a dead end, the kitchen fits ok.
The One With Ross's Denial - S6-E3
Continuity mistake: When Joey is interviewing the potential roommate and Chandler comes in, Joey's stance changes a few times. His grip on the application form changes, and when he points to the bathroom his arm is in a slightly, but noticeably, different place in the next shot. (00:11:10)
The One With Joey's Porsche - S6-E5
Continuity mistake: When Ross is talking to his divorce lawyer there are 2 pens in a holder on the desk. Throughout the scene they vanish and appear randomly. (00:10:50)
The One With The Ring - S6-E23
Continuity mistake: Paul finally opens up, and cries like a baby to Rachel. While talking to her at the breakfast bar in the kitchen (when Rachel is trying to distract him with sex), he's wearing a white linen shirt that constantly changes between tear-stained and wrinkled to ironed and clean. (00:14:35)
The One Where Paul's The Man - S6-E22
Continuity mistake: When we hear the recording of Chandler answering the phone, it sounds nothing like what Chandler actually said. (00:13:00)
The One With The Proposal, part 2 - S6-E25
Visible crew/equipment: When Chandler walks in and sees Monica, the boom mic is visible above Monica's head. (00:17:45)
The One With Joey's Porsche - S6-E5
Revealing mistake: When Phoebe knocks over the vase she glances at it just before throwing the diaper. (00:15:10)
Suggested correction: The bin for the diapers is near the vase, and she glances at that before throwing the diaper.
The One With The Joke - S6-E12
Continuity mistake: Joey and Chandler are talking about money, and Joey picks up the Playboy magazine saying Ross gave him reading material. He sets it down on the counter, but in the next shot of the magazine, it has moved farther down the counter. (00:03:10)
The One Where Ross Dates a Student - S6-E18
Visible crew/equipment: Just after Ross' girlfriend leaves the Central Perk, Ross walks towards the couch. Just before Rachel starts talking, the stage lights can be seen reflected in the glass above the entrance. (00:17:00)
The One With Rachel's Sister - S6-E13
Continuity mistake: When Jill drops her shopping bags on the coffee shop table, the small blue Tiffany's bag is visible on the end of the 'line'. But it is not visible in any shots after Rachel comes in. Additionally, when Rachel grabs the bags and leaves, Ross seems to pick the little blue bag up off the floor, though it is not shown how the bag got there. (00:05:35)
The One Where Chandler Can't Cry - S6-E14
Continuity mistake: In the cafe, Ross says to Rachel, "I'll tell her we can't see each other any more," and we see Rachel bring her hands down from her face. However, in the previous shot we had already seen her lower her hands. (00:03:25)
The One On The Last Night - S6-E6
Continuity mistake: At the end when Monica and Chandler hug, Monica's arms keep going from under to over Chandler's arms as the cameras switch many times. (00:20:00)
The One That Could Have Been, part 1 - S6-E15
Continuity mistake: Near the start, Chandler is sitting in the coffee house in the big chair. When he's talking to Joey about money, his feet change positions every two seconds. On the floor, crossed, resting on the table, the list goes on and on. (00:04:55)
The One Where Paul's The Man - S6-E22
Continuity mistake: When Monica is blaming Phoebe for Chandler hearing the wedding message, Phoebe puts the magazine down on her lap and it's closed, but in the next shot it's open. (00:15:40)
The One With The Proposal, part 2 - S6-E25
Audio problem: In the pizza place, after Chandler tells Monica to "put down [her] copy of The Rules..." you hear Monica say, "You know what. I gotta go" when her lips aren't moving. (00:04:26)
The One Where Ross Got High - S6-E9
Audio problem: When Ross and Joey go into the bedroom, you can hear the duck in the background, even though the chick and the duck should be in the other apartment and aren't even in this episode. (00:12:53)
The One With The Joke - S6-E12
Continuity mistake: In the coffee shop Phoebe is not in the scene. After Joey puts his apron on, the camera shows Phoebe is next to Rachel. Monica asks Joey if he works there, he says no, a customer calls "waiter" and in a full view of the coffee shop Phoebe is no longer there. (00:09:45 - 00:10:55)
The One Where Ross Got High - S6-E9
Continuity mistake: When Ross asks Rachel to step into the hallway, we see the whipped cream atop the trifle dessert plates on the table, but while Joey gives everyone acting lessons all the whipped cream is gone, then the dollops of whipped cream reappear once again.
The One With The Proposal, part 1 - S6-E24
Continuity mistake: When the waitress opens the door to the kitchen to tell Monica about a complimentary customer, in the first shot the waitress pulls the door open and stands in front of it, but in the next shot she's pushing the swing door into the kitchen poking her head in to talk to Monica. (00:20:35)
