The One Where They All Turn Thirty - S7-E14
Plot hole: There's no way Phoebe has lived to 31 without knowing her birth date. She's had "real" jobs (like the massage parlor) and those require social security numbers and accurate birth dates. She didn't go to high school, but she mentions classmates, so she must have gone to elementary/middle school, and those required birth dates even in the '70s and '80s. She's also "lived in Prague," which she couldn't have visited without a passport - which requires a birth certificate.
The One Where They All Turn Thirty - S7-E14
Continuity mistake: In The One Where They All Turn Thirty, it is Rachel's birthday. They show flashbacks of all the other Friends' thirtieth birthdays despite Monica's birthday supposedly being months after Rachel's. Plus, earlier on in the show Joey was 25 when Monica was 26, and since Monica and Rachel were in the same grade Joey should actually be a year younger than them, not a year older.
The One With Joey's New Brain - S7-E15
Character mistake: After Susan Sarandon slaps Joey the first time, after he tells her that her character is dying on DOOL, she turns away and right before she is off camera she smiles, instead of maintaining her anger. (00:06:05)
The One With Joey's New Brain - S7-E15
Continuity mistake: When Joey is talking to the woman whose brain he receives, as the shot changes she is holding a glass, then a cigarette then a glass again, with no time to change objects, let alone anywhere to put the other. (00:06:05)
The One With Joey's New Brain - S7-E15
Visible crew/equipment: When Monica and Chandler are going over to the window to see Ross playing the bagpipes, the head of a crew member is visible on the left side of the screen, standing by the framed poster. (00:07:30)
The One With Joey's New Brain - S7-E15
Continuity mistake: When Chandler, Ross and Monica are in Central Perk discussing playing bagpipes, and Ross says, "Decide whatever you want," he is gesturing with his right hand up and with an open book in his left hand. When the camera angle changes, the book is closed and is now in his right hand. (00:15:30)
The One With Joey's New Brain - S7-E15
Other mistake: In the scene where Phoebe and Rachel are talking in Phoebe's apartment and Tom is waiting at the door, after Phoebe says "you are such a good friend", we hear someone say Tom, meaning its Tom's turn to talk. Extended episode only. (00:20:55)
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 The Truth About London - S7-E16
Continuity mistake: At the beginning when Chandler is talking about two reasons to pick a minister, he counts them using his left hand. However, in the wide shot straight afterward his right hand has two fingers up and his left hand is in his lap. (00:02:00)
The One With The Truth About London - S7-E16
Continuity mistake: In the opening credits, Monica and Chandler are talking about which minister to use. Chandler's feet are crossed and on the table; at first his left leg is over his right, then in another shot his right leg is over his left. (00:02:45)
The One With The Truth About London - S7-E16
Continuity mistake: After Rachel shows Ben the pencil and quarter prank, she lays the pencil down and it is pointing straight ahead. When the pencil is shown again it has moved. (00:05:45)
The One With The Truth About London - S7-E16
Revealing mistake: When Monica gives Phoebe the headache medication (Hexadrin) she, not only doesn't take the lid off - and therefore fails in pretending to put it back on - but also doesn't actually give Phoebe anything. Extended episode. (00:07:30)
The One With The Truth About London - S7-E16
Continuity mistake: When Joey is reading his speech about all the giving and receiving, Chandler has his legs on the table at the coffee shop. You can see his shoes on the table when they show Joey, but when they change the shot to Chandler his legs are on the floor and crossed. (00:10:55)
The One With The Truth About London - S7-E16
Continuity mistake: When Rachel goes to Carol's house and tries to tell Ben to stop playing pranks, her bag changes from being on her shoulder to in her hand in almost every shot. (00:12:25)
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 The Truth About London - S7-E16
Continuity mistake: In the flashback, Chandler says to Joey that he is watching a movie when the camera cuts to show the blank screen. In the reflection, you can see that there is no-one present in the room. (00:18:20)
The One With The Truth About London - S7-E16
Other mistake: Right at the very end, when Joey is in the fat-suit and picks up a piece of food and says "How you doin'?" he doesn't put it in his mouth, he just lifts it to his lips, stops, and tries to stay still. If this had been a freeze on the part of the director then fair enough, but it isn't as he and particularly Monica are still moving. It just looks rather corny and amateur, as though they are waiting for the "cut" to be called. (00:28:00)
The One With The Truth About London - S7-E16
Audio problem: During Rachel's scene sitting on the couch with Ben talking about her and Ross and her sisters, Rachel's mouth moves in any scene showing Ben, but without her being heard.
The One With The Truth About London - S7-E16
Continuity mistake: In the flashback scene where Chandler and Monica are in the hotel room, there are three paintings on the wall of flowers, etc. In the original scene from ‘the one with Ross' wedding part 2' the pictures are completely different.
The One With The Truth About London - S7-E16
Visible crew/equipment: As Joey is entering Monica and Chandler's apartment, there is a black microphone visible for a few seconds moving above Joey's head as he is walking towards Monica and Chandler at the table.
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