The One With The Hypnosis Tape - S3-E18
Continuity mistake: When Frank and Alison kiss in the coffee house for the first time, a woman in the background is handed money or something. This is shown twice. (00:04:50)
The One With The Hypnosis Tape - S3-E18
Continuity mistake: After Mrs Knight sits down with Phoebe's brother in Central Perk, keep an eye on the strap of her handbag. It starts over her shoulder, then moves around and changes position at least half a dozen times. (00:04:40)
The One With The Hypnosis Tape - S3-E18
Continuity mistake: Just after Chandler has used the chapstick, in a shot from the side the stick is in his right hand, and then in the next shot he is instantly putting a tissue (which wasn't visible before) up to his lips, and the stick has moved to his left hand. (00:10:45)
The One With The Hypnosis Tape - S3-E18
Continuity mistake: In the diner scene, Rachel makes the comment about working in fashion and straight men, and her left hand is empty; in a flash, a piece of bread appears without her picking it up. (00:06:40)
The One With The Hypnosis Tape - S3-E18
Continuity mistake: When Frank Jr is sitting in front of the TV while Davey and Goliath is on, his hand is along the edge of the TV set; however when Phoebe walks in, his arm is straight out. Then when Mrs Knight comes in, his head is straight down and the arm is back along the edge. (00:15:15)
The One With The Hypnosis Tape - S3-E18
Continuity mistake: When Chandler asks for a chapstick, his hands are in his coat pockets; then Rachel asks "How are those tapes working out for you?" and his hands are clasped in front of him. (00:10:00)
The One With The Hypnosis Tape - S3-E18
Continuity mistake: When Monica serves cheesecake to Pete, she goes to put the lid back, but in the next shot the lid is not there. (00:07:16)
The One With The Hypnosis Tape - S3-E18
Continuity mistake: When Pete is trying to ask Monica out at the diner she works at, she rejects him while placing the bell jar over the cheesecake and the pie server on the counter. In the next shot, the bell jar is nowhere to be seen and the pie server is up on the cake stand with less cheesecake. Then the bell jar reappears over the cheesecake. (00:07:00)
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