The One With The Bullies - S2-E21
Visible crew/equipment: When Phoebe goes to visit her father, there is a little dog outside. Phoebe gets back in the car and the dog jumps up the side of it. When he finally gets part way through the window, the top of the dog-handler's head is visible through the car window. (00:07:00)
The One With The Bullies - S2-E21
Continuity mistake: When Phoebe calls by the house with the dog, a woman with a handbag is visible in the background, going into her house. About ten seconds later we see the same woman with the handbag walk towards her house again. (00:15:40)
The One With The Bullies - S2-E21
Visible crew/equipment: When Chandler falls behind the couch, the mat he lands on is visible.
The One With The Bullies - S2-E21
Visible crew/equipment: While driving the cab, Phoebe is wearing a blue shirt. When the car stops suddenly, a crew member wearing a white shirt is visible driving the car.
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