The One With Five Steaks and an Eggplant - S2-E5
Continuity mistake: When Chandler picks up the phone, he says "Bob here" and Ross is sitting by the bar on the living room side. When the scene starts again after the credits, Ross is getting a drink out of the refrigerator. (00:01:00)
The One With Five Steaks and an Eggplant - S2-E5
Continuity mistake: When Ross is giving his toast to Monica, when he's finished he drinks from his glass. Later when Chandler arrives, it is still at the same level. (00:07:10)
The One With Five Steaks and an Eggplant - S2-E5
Continuity mistake: When Chandler is seducing Jade in Central Perk, he turns to face Ross after handing her the tissues. The camera then cuts to another angle where he is still facing Jade, and then he turns again to face Ross. (00:06:40)
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