The One Where No One Proposes - S9-E1
Revealing mistake: When the nurse hands Emma to Rachel, you can tell it's not a real baby. (00:08:10)
The One Where No One Proposes - S9-E1
Revealing mistake: When Rachel is breastfeeding Emma for the first time, the baby's head is constantly moving in the same repetitive pattern suggesting it is one of those life-like dolls. Babies do not move their heads like that. (00:08:20)
The One Where No One Proposes - S9-E1
Revealing mistake: While everyone's looking at Emma through the window, when Jack makes the comment about the first grandchild, someone in the background walks by and causes the hallway's set wall to wobble behind them.
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