The One With the Breast Milk - S2-E2
Continuity mistake: When Phoebe tests then tastes the breast milk, Ross is holding Ben. Every time the camera goes back to Ross, the baby has his dummy in, then out, then in again, but no sight of Ross putting it in his mouth.
The One With Joey's Interview - S8-E19
Continuity mistake: In the opening scene, Joey is holding the Soap Opera Digest magazine. In one shot it is open but folded, then in another it is open all the way, then it's folded again, then it's open again, then it's closed, and then it's folded again. The change is never shown.
The One With All The Haste - S4-E19
Continuity mistake: The singing neighbor is more than halfway done tying his tie but when Rachel yells at him, the tie is merely draped around his neck.
The One Where Joey Moves Out - S2-E16
Continuity mistake: When Joey and Chandler are at Joey's colleague's brunch, you can see a big wall clock in some shots. You can see it when Chandler says: "Wow, there's my fantasy's come true" with the minute hand at five to the hour. Just a few seconds later, when Joey says: "Can you see me in a place like this?" it can be seen when Chandler is in shot, and the minute hand is now at 20 to the hour. (00:05:40)
The One Where Heckles Dies - S2-E3
Continuity mistake: After she breaks Rachel's seashell lamp, Monica puts her jacket over the back of the big chair. When Chandler sits on it, the jacket keeps disappearing and reappearing in almost every shot. (00:17:35)
The One With All The Cheesecakes - S7-E11
Continuity mistake: When Ross and Monica are at the wedding reception talking to the other guests at their table, a lady wearing a red scarf is standing behind them with her back turned. Throughout the scene the red scarf keeps changing position very quickly - in one shot it's slid down one shoulder, then back up in the next and then slid down again. At the end of the scene it's off her back entirely and she has just slung it over her arms. (00:12:15 - 00:13:15)
The One After Ross Says Rachel - S5-E1
Continuity mistake: Between season 4 and season 5 some of the furniture in Chandler's and Joey's hotel room is changing. In TOW Ross' Wedding the three big pictures over the beds show dark spiky plants like ferns and palm trees (as can be seen in the scene where Joey shows Chandler the video with Fergie). In this episode these pictures are completely different - they show a red flower, a sunflower and a dark green plant. The two pictures next to the door are now much smaller in bigger frames and the lamp on the night table between the beds which had a white shade in season 4, now has a black shade. The nightstand between the two beds also has a different shape.
The One With Rachel's Inadvertent Kiss - S5-E17
Continuity mistake: When Rachel returns from her first interview at Ralph Lauren she takes out a bottle of water out of the fridge. In the following shot her hands are empty and there are only Chandler's and Joey's bottles on the table. Rachel's bottle reappears on the table next to Chandler's and Joey's bottles (that are also standing closer together than before) for a moment just when Chandler starts saying "Well, you could have tried not kissing him" and then vanishes again. (00:06:20 - 00:07:15)
Continuity mistake: Joey's bedroom door opens and closes as the camera goes between him and Monica and Chandler when he is telling him he doesn't want to see them kissing.
The One Where Ross and Rachel...You Know - S2-E15
Visible crew/equipment: While Ross is trying to fix the position of the cavemen in the museum, a boom mic can be seen above his head.
The One With Rachel's Inadvertent Kiss - S5-E17
Continuity mistake: Joey is watching Ross from Monica's window and goes searching for the hot girl. The exterior shot crossing the street between buildings is inconsistent with the interior shots, which show them looking at each other across an alley with no visible fire escapes. The exterior shot crosses a street to a building with street-facing fire escapes on every apartment.
The One With The Lottery - S9-E18
Continuity mistake: Joey's thumb on the wishbone changes positions as the camera switches between Joey and Monica.
The One with the Candy Hearts - S1-E14
Continuity mistake: In the scene where Ross and Carol are talking and Carol says that all he needs is to find a woman who likes men, a woman comes across the room walking in high heels. The shot is wrong because we see her up until she's half the way through the table, and the next shot shows her four steps back. (00:23:10)
The One With The Football - S3-E9
Continuity mistake: When they are talking about the Geller Cup, Monica is looking at Ross and then looks down. But when the camera angle changes, she is still looking at Ross and then looks down again.
The One With The Giant Poking Device - S3-E8
Continuity mistake: When Chandler is breaking up with Janice and she walks away trying to shake him off, her jumper is untied. When Chandler says "You can't go, I have your shoe" we cut back to Janice and her jumper has been tied at the bottom.
The One With The Giant Poking Device - S3-E8
Continuity mistake: When Rachel and Monica are stressing about the bump on Ben's head, Rachel's hair keeps moving from tucked behind her ear to hanging loosely in her face between shots.
The One With The Metaphorical Tunnel - S3-E4
Continuity mistake: In the scene where Chandler is sitting on the cabinet talking to Rachel and Monica, Rachel is holding an ice-cream bucket and a spoon. However, they keep showing up on the counter and then back in her hands between shots.
Continuity mistake: When Rachel tells Ross that she is still in love with him, her hair keeps changing from behind her ear to down when the camera changes angles.
The One With The Dirty Girl - S4-E6
Continuity mistake: Rachel is working on the crossword puzzle and her legs are crossed (first left over right) and they switch back and forth between shots (about four times) without any time to do so.
The One With The Inappropriate Sister - S5-E10
Continuity mistake: When Joey and Phoebe are talking to each other on the couch, Rachel tucks her hair behind her ears, but in the next shot it's moved.
Answer: The statements that she's contradicting (that it is common, it happens to every guy, and it's not a big deal), are the things that a woman commonly says to a man who is suffering from erectile difficulty, typically to assuage his bruised ego. However, most men do not believe that these statements are true, as evidenced by Chandler's outburst. He's so caught up in the proof that women are lying about it that he gives himself away.
Rooster of Doom