Visible crew/equipment: In the scene where Chandler is talking to Rachel and Ross about how Janice thought that he had somehow called her fat, if you watch Monica's closet in the back, you can see the shadow of someone walking past, under the door. (00:05:20)
Continuity mistake: When Pheobe is talking to Ursula's stalker, her hands move places with no time to do so. (00:02:45)
Continuity mistake: Right at the end when Ross hits Chandler with his rolled up magazine, he only folds over one-third of the magazine onto the middle third. When it cuts to him hitting Chandler (without a time delay between him hitting Chandler and folding the magazine) the magazine is fully folded over. (00:21:30)
Continuity mistake: When they are talking about sperm donation, Joey is eating a cracker with jam on it. Between shots it instantly rotates in his hand. You can tell because the jam goes from being on the top to the bottom side, and because of the way he is holding it you can see there is only jam on one side. (00:14:15)
Continuity mistake: When Phoebe is talking to her stalker for the first time, at one point, he tips the flowers to the side when Phoebe says, 'Well, this is awkward,' and he puts his left hand on the end of the stems. In the next shot he is holding them with both hands. (00:02:55)
Audio problem: In the scene where Malcolm is talking to Phoebe in the subway, you can hear him but his lips aren't moving.
Visible crew/equipment: When Ross and Rachel realise they are in an empty apartment, studio lighting can be seen over their heads in the ceiling as Ross leads Rachel into the centre of the room. (00:04:35)
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