The One In Massapequa - S8-E18
Revealing mistake: Towards the start there's a stand-in for Jack Geller, as he is speaking to Ross and Rachel, who is obviously not Elliot Gould. Also, in the first picture, there is a great look alike standing behind and to the right of Jack. (00:06:00)
The One In Massapequa - S8-E18
Visible crew/equipment: After the anniversary party, when Rachel and Ross are back at the apartment and Ross tells her that it was the easiest four hundred bucks he ever made, Rachel gets up and just as she walks around the couch we can see the reflection of the cameraman/crew member in the mirror on the wall, at the right side of the screen.
The One In Massapequa - S8-E18
Character mistake: In the early years, the gang are talking about their pets dying and their parents saying they sent them to a farm and Ross thinks that actually exists. He said that they sent their dog Chee Chee there and HE could run about chasing animals. Then in TOI Massapequa, Monica is preparing her speech and she tells Chandler about Chee Chee and said SHE died when Monica was in school, and when Parker asks whose dog it is, Monica says HE's my old dog. Then during her speech, Monica says HER and Nana are gone. (00:15:30)
The One In Massapequa - S8-E18
Continuity mistake: In The One In Massapequa, Jack Gellar is eating food off a stick. When he finishes he holds the stick while Rachel asks Jack if he has any pearls of wisdom. We can see the stick over Judy's shoulder. In the next shot the stick is gone from his hand, then we see Judy put it down on a table, then it reappears in his hand, before disappearing for good. (00:05:05)
The One In Massapequa - S8-E18
Audio problem: When Monica is preparing her speech, she stands up to show Chandler her note card, but when you can hear her say "Hey, check this out," her lips don't move. (00:02:20)
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