The One Where the Monkey Gets Away - S1-E19
Continuity mistake: When Phoebe gets hit with the tranquilizer she falls on the couch with no dart in her leg. When she stands up it appears out of nowhere. (00:15:50)
The One With Chandler's Dad - S7-E22
Continuity mistake: When Monica and Chandler are in Las Vegas watching the burlesque show, Chandler turns the light on the middle of the table off to "hide" from his Dad. When Monica calls out saying "Waiter. Waitress.", the light is suddenly back on and remains on for the rest of the scene. (00:15:50)
The One With Rachel's Date - S8-E5
Continuity mistake: When Ross says goodbye to Rachel near the end, she lowers the bag of sweets to her waist. Then in a close up of her looking thoughtful it's up by her chest. (00:20:10)
The One With Ross' Step Forward - S8-E11
Continuity mistake: In the scene when Phoebe comes in to tell Rachel she is sorry about the whole thing with Roger, Rachel is eating ice cream, and sets it on the counter and in the next shot sets it down again. (00:23:25)
The One With The Dollhouse - S3-E20
Continuity mistake: When Monica is telling Rachel that guys always say they are going to call, but it doesn't mean they will, she is eating yogurt; in the next shot she has a cup ready to drink out of. (00:14:30)
The One Where They're Up All Night - S7-E12
Continuity mistake: There is a long shot of Rachel and another person sitting on the sofa and Rachel's wine glass is almost empty. She then goes over to the the counter to fill it up. However, before she starts to fill it, a significant quantity of wine can be seen in the glass. (00:07:35)
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 with Mrs. Bing - S1-E11
Continuity mistake: When they are all eating at the restaurant and Mrs. Bing is telling Rachel how to write a book, the amount of food on Rachel's plate changes between shots without her touching it. (00:06:55)
The One Where Monica Gets a Roommate - S1-E1
Continuity mistake: At the end of the episode, as a customer in Central Perk asks Rachel for more coffee, Chandler has set his cup of coffee on the table. In the next shot, he is holding it again. (00:28:05)
The One With Phoebe's Dad - S2-E9
Continuity mistake: Phoebe says to Chandler that there is no seatbelt as the paramedics had to cut it. but a few seconds later, you can see a seatbelt. (00:12:25)
The One With a Chick. And a Duck. - S3-E21
Audio problem: At the end of the program, Joey asks Chandler if a chick can swim. They put the chick in the bath, but it's still able to chirp even though it is supposed to be under water. (00:21:20)
The One Where Underdog Gets Away - S1-E9
Continuity mistake: When Rachel gets her mail off Monica she puts it down on the couch and picks up a sealed envelope. The camera cuts and the envelope is now open with no time to open it. (00:07:25)
The One With The Rumor - S8-E9
Other mistake: Monica and Chandler's wedding is May 2001 (we are given the dates by the characters on the show, so it doesn't matter when the show aired.) And Rachel reveals at the wedding that she is pregnant, so that means she got pregnant in April or so of 2001. "The One With The Rumor" aired and is set to take place at Thanksgiving 2001, during which time Rachel should be 7 months pregnant. But her stomach's flat as a pancake. (00:01:15)
The One Where Rachel Has a Baby, part 2 - S8-E24
Continuity mistake: While Rachel is having her baby she grabs Ross by the shirt and says 'you do it for me' in the next shot her hand is no-where near Ross. She couldn't have put her arm down that quickly. (00:33:50)
The One With The Jellyfish - S4-E1
Audio problem: When Phoebe is knocking on her sister Ursula's door to tell her about finding her birth mom, the third knock is heard a split second before you see Phoebe's hand action. (00:12:15)
Continuity mistake: Rachel and Phoebe are in the Central Perk, talking about leaving the group, and a jacket and a handbag are hanging on the arm of the chair behind Rachel, slightly to her left. Between shots it changes from just the jacket, then just the handbag and so on. This continues throughout the scene when Ross comes in and Phoebe leaves. As she gets up you see both again, however Rachel does not move enough to just show one and hide the other. (00:16:00)
Revealing mistake: When Chandler and Monica try to change the babies, Courteney Cox's pregnant belly is visible. (00:16:20)
The One With Phoebe's Ex-Partner - S3-E14
Visible crew/equipment: When Monica and Chandler are discussing the date he had with Ginger, when he says, "She's great looking," two stage lights are visible in the background. This mistake is visible for a long period of time, where it's slightly visible, shown in shadows, and largely visible as Chandler and Monica are talking. (00:14:30)
The One with Two Parts: Part 2 - S1-E17
Continuity mistake: Just before Ross drops the cake, Rachel is pouring crisps into a bowl with her left hand holding the bottom of the bag. In the next shot, she is holding the bottom of the bag with her right hand. (00:05:50)
The One With The Video Tape - S8-E4
Continuity mistake: As Rachel says, "Let's be honest" to Ross, her hands are in her lap. The camera cuts and now she is gesturing with them. (00:03:30)
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