The One With The Fertility Test - S9-E21
Visible crew/equipment: When Monica and Chandler are on the couch in the fertility clinic after Monica says "Nobody's gonna wanna watch that" the camera switches to a wider shot. When it does this the boom mic swiftly moves out of view. (00:12:20)
The One With The Fertility Test - S9-E21
Visible crew/equipment: After Chandler tells Monica the results of the fertility tests, when it cuts to Phoebe as the receptionist says good morning to her, the camera can be seen at the left side of the screen.
The One With The Fertility Test - S9-E21
Visible crew/equipment: When Chandler is given the cup at the clinic, a boom shadow can be seen on the wall. (00:12:50)
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