The One Where Monica Gets a Roommate - S1-E1
Other mistake: At the end when Ross and Rachel split an Oreo, you can see that Rachel is holding 2 parts and Ross somehow still has one. (00:20:38)
Character mistake: In some episodes the facade of Central Perk is shown. On the window the word "cappuccino" is misspelled, it says "cappucino."
The One with the East German Laundry Detergent - S1-E5
Continuity mistake: When the horrible woman says "no suds, no saves", Rachel's hands suddenly appear on her basket. (00:11:30)
The One with the Candy Hearts - S1-E14
Visible crew/equipment: Just as Joey and his date are leaving, a stage light and the top of the set drop into view above Chandler. (00:08:10)
The One with the East German Laundry Detergent - S1-E5
Continuity mistake: Phoebe says she's going to break up with Tony, and Monica has her cheque book in her hand pointing away from her lap. Camera cuts and now it's in her lap. (00:03:00)
The One with the Dozen Lasagnas - S1-E12
Audio problem: The very last line of the episode (Monica saying "and I'm gone") is an overlay. (00:22:40)
The One with the East German Laundry Detergent - S1-E5
Continuity mistake: At the start, Chandler and Joey have their hands outstretched. Camera cuts and now Chandler's hand is lowered. (00:00:50)
The One with George Stephanopoulos - S1-E4
Continuity mistake: Monica asks Phoebe if she has a plan to which she replies she doesn't even have a "Pla." During this, her hairs position on the futon changes between shots. (00:14:40)
The One with George Stephanopoulos - S1-E4
Continuity mistake: The facial expression of the receptionist changes drastically between instant cuts when she says the line "any minute now" (00:14:00)
The One with George Stephanopoulos - S1-E4
Continuity mistake: The way the receptionist in the hospital holds the candy bar differs between the several camera angles. (00:13:30)
The One with George Stephanopoulos - S1-E4
Continuity mistake: When Ross gets hit with the puck, we see it flying towards him. Camera cuts and the puck has simply vanished and yet Ross acts as though he has been hit. (00:12:45)
The One with the East German Laundry Detergent - S1-E5
Visible crew/equipment: When the horrible woman enters, a tape marker is visible on the floor by the machines. (00:11:20)
The One with the Thumb - S1-E3
Audio problem: When Monica is first seen in the kitchen complaining about taking a guy home, the other chef is cutting some items up. However, the audio of the knife clicking as it hits the board is overdubbed. (00:08:00)
The One Where Monica Gets a Roommate - S1-E1
Visible crew/equipment: We get a close-up of the coffee pot when Rachel asks if anyone would like some. In this shot, there are 3 stage lights reflected clear as day. (00:27:50)
The One Where Monica Gets a Roommate - S1-E1
Continuity mistake: Near the end when Phoebe says to Monica, "C'mon give me your feet" she puts the red pen down on the blue paper. When Monica sits down though, the red pen is on the table and not the blue paper. (00:23:40)
The One Where Monica Gets a Roommate - S1-E1
Continuity mistake: When Joey makes the joke about Ross being 8, Ross has his right left hand lowered. Camera changes to a different angle and it's raised, before switching back to the 1st angle and being lowered again. (00:15:50)
The One Where Monica Gets a Roommate - S1-E1
Continuity mistake: The way Ross holds the can of beer changes between the full on shots and the shot of Chandler and Joey when just the can is visible on the side of the screen. (00:12:40)
The One Where Monica Gets a Roommate - S1-E1
Continuity mistake: When Joey hides the bracket in the plant pot, the instruction sheet that is on the bookcase disappears instantly. (00:12:20)
The One With the Baby on the Bus - S2-E6
Continuity mistake: When Chandler and Joey fetch Ben from the Department of Health Services, as they say they're both the baby's father, Chandler puts his arm around Joey and Joey takes his hand. When the angle changes you can see Joey's shoulder and Chandler's hand isn't on there. When it cuts back to the front view, his arm is around Joey again. (00:15:10)
The One With Barry & Mindy's Wedding - S2-E24
Continuity mistake: Phoebe takes out her gum before kissing Joey. After she kisses him, she makes a comment about it and her mouth is empty. In the next shot, she sits down and is chewing. But she doesn't put the gum back in. (00:02:22)
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