The One With The Cheap Wedding Dress - S7-E17
Continuity mistake: Monica chooses a wedding dress at an expensive boutique, then later goes to a discount store to buy the same style dress at a half-off sale. The dress she buys is different from the one in the boutique, having wider and frillier straps. When she tries it on later at the apartment, it is now the same style as the one at the boutique. (00:04:00 - 00:07:15)
The One With The Cheap Wedding Dress - S7-E17
Continuity mistake: In the shot where Joey meets Kristen the lights in the store window behind them are switched on. On the DVD at 05:19, you can see that the "CD" light is illuminated in blue. However, at 05:36 where they both shake hands, all the lights are switched off. (00:05:15)
The One With The Cheap Wedding Dress - S7-E17
Continuity mistake: Chandler's chair appears in this episode again, although it was broken in 7/13 and thrown out. It is not in the room in 7/14-16, but in 7/17 it's there again, then it is gone again in 7/18.
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