
The One with the Candy Hearts - S1-E14
Continuity mistake: Just before Carol and Susan enter the restaurant, Ross reaches for the menu with his left hand and his right hand is under the table. In the next shot his right hand is holding onto a cup on the table. (00:11:20)

The One with Two Parts: Part 1 - S1-E16
Visible crew/equipment: At the Lamaze class just before Ross and Susan argue about who should lie on the floor, a boom mic can be seen in the top left corner of the screen. (00:08:50)

Continuity mistake: When Monica and Rachel are discussing Phoebe, Rachel's hands go from playing with the table to dry washing depending on the shot. (00:12:30)

The One with Mrs. Bing - S1-E11
Continuity mistake: In the final scene Rachel passes out copies of her draft for her book. She gives out all her copies and asks for their opinion. However, near the end of the scene after waving her arms around empty handed a copy of her script magically appears in her hands. (00:21:10 - 00:21:45)

Continuity mistake: Ross always had an end apartment. At some point in Season 8, his apartment became a middle apartment. In earlier season, when Joey had mistaken Ross' for the hot girl's apartment, it showed the apt as an end apt. In TOW Joey tells Rachel, when Joey asked Rachel to have dinner at Ross' apt, it showed another hallway where Joey came from which is supposed to be the wall/ Ross' kitchen.

The One with the Dozen Lasagnas - S1-E12
Continuity mistake: During the song at the beginning of the episode, keep your eye on Ross's mug. He is holding it in his lap, then there is a shot of Monica with Ross's empty saucer on the table. In the next shot, the mug has appeared on the saucer. (00:00:30)

The One with Mrs. Bing - S1-E11
Continuity mistake: When Joey asks Ross 'how could you let this happen' in the hall, his sleeves are down to his wrists. In the next shot, they are rolled up. (00:10:25)

The One with Two Parts: Part 1 - S1-E16
Continuity mistake: When Chandler tries to fire Nina, he holds his left hand to his face. In the next shot he is holding his right hand up. (00:10:20)

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 After the Superbowl, part 2 - S2-E13
Continuity mistake: When Susie is asking Chandler to wear her undies, her hand is on his neck. In the next shot it is gone, and then it is back again. (00:08:45)

The One with the East German Laundry Detergent - S1-E5
Continuity mistake: While Rachel and Ross are at the laundromat there's laundry detergent, softener, bleach, etc., atop the soda machine, some of which change position or vanish in consecutive shots.

The One Where Monica Gets a Roommate - S1-E1
Continuity mistake: Before Monica stomps on Paul's watch, the chair closest to the fridge does not have fabric backing, then when Ross eats the Oreo and walks toward his jacket the chair closest to the fridge is now fabric backed and his jacket hangs from a chair with no fabric, plus there are only four chairs around the table. However, when Ross picks up his jacket this chair is now fabric backed, the chair closest to the fridge doesn't have a fabric back yet again, and there are now five chairs around the table. (00:27:00)

The One With The Giant Poking Device - S3-E8
Visible crew/equipment: Right after the intro, in the first shot of Gunther, Ross, and Rachel, just as Ross says, "Thanks, Gunther," the camera is visible at the left side of the screen. (00:02:00)

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 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)

The One With The Proposal, part 1 - S6-E24
Visible crew/equipment: After Chandler tells Monica about the interesting website and fakes his opinion of marriage, right after Monica says, "Well, that's good to know," in the next wideshot the camera can be seen at the right side of the screen. (00:20:15)

The One With Monica's Boots - S8-E10
Visible crew/equipment: When Joey is talking to Bobby and Dina, lights and a boom mike can be seen at the top of the screen. (00:18:40)

The One With The Halloween Party - S8-E6
Visible crew/equipment: Right after Joey has finished his impersonation of Chandler, kids can be heard knocking on the door. When the camera pans to Rachel, stage lights can be seen in the top right-hand side of the screen. (00:05:15)

The One With the Pediatrician - S9-E3
Continuity mistake: After Rachel's 3 AM phone call to her pediatrician, when Rachel suggests using Dr. Gettleman she raises her left hand and points at Ross, but in the next closeup it's her right arm that's raised.

The One Where Ross Can't Flirt - S5-E19
Continuity mistake: After Joey runs out of the apartment to go make the fake videotape, when it cuts to Rachel walking back into the apartment the table with the tablecloth is quite far away from the front door, but when Caitlin knocks and Ross rushes to go flirt with her that table is near the door. (00:13:35 - 00:15:15)
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