The One with the Stoned Guy - S1-E15
Continuity mistake: When the stoned guy eats all the shrimp ravioli, he eats everything including the garnish. When we next see the plate, the garnish has returned. (00:17:30)
The One with the Stoned Guy - S1-E15
Continuity mistake: When the stoned guy says they should make macaroni and cheese, Monica holds out her hands. In the next shot, her hands are clasped together. (00:18:50)
The One with the Stoned Guy - S1-E15
Continuity mistake: When Chandler says he can't work out what he wants to do working at his job, he is standing behind the sofa. In the next shot, he is in front of the sofa sitting down. (00:02:50)
The One with the Stoned Guy - S1-E15
Continuity mistake: Just before Chandler tells everyone he quit, he holds out both hands in front of him. In the next shot, his left hand is by his side. (00:02:05)
The One with the Stoned Guy - S1-E15
Continuity mistake: In the scene where Monica is explaining to Rachel that she has hired her friend Wendy as her waitress, Rachel is holding a water bottle in one hand and the cap in the other. Monica moves towards her and Rachel is pointing her hand in Monica's direction and then in the next shot we see Rachel from another angle and her hand is holding the cap on top of the bottle too fast to have happened in normal time. (00:08:40)
The One with the Stoned Guy - S1-E15
Continuity mistake: When Chandler shows Phoebe his office he opens the blinds. In the next shot a pile of books have appeared on the window ledge. (00:14:40)
The One with the Stoned Guy - S1-E15
Continuity mistake: During the scene when Chandler arrives with his test results, Phoebe is reading a book with a red section on the left hand page. In the next shot, the red on the page has vanished. Then, in the next shot, the red page is back again. Also Phoebe's left hand moves between shots. (00:07:15)
The One with the Stoned Guy - S1-E15
Continuity mistake: After Chandler walks in on Ross and Joey talking dirty, Ross is holding his right hand up as he and Joey start to explain to Chandler. In the next shot his arm is by his side. (00:13:10)
The One with the Stoned Guy - S1-E15
Continuity mistake: When Chandler says Ross isn't speaking metaphorically, he gestures with his right hand. In the next shot, both his hands are in his pockets. (00:06:05)
The One with the Stoned Guy - S1-E15
Continuity mistake: After Chandler walks in on Ross and Joey's dirty talking, Chandler walks towards the door and Joey turns to Ross. In the next shot Joey has turned around and is facing Chandler. (00:13:15)
The One with the Stoned Guy - S1-E15
Continuity mistake: When the monkey is hanging off Ross's date's hair, in one shot he is hanging upside down, then in the next he is hanging the right way up. (00:06:35)
The One with the Stoned Guy - S1-E15
Continuity mistake: When Phoebe asks Chandler if he wants to be a chef, Monica says 'Hi, there' with her right hand raised. In the next shot, it is on her lap. (00:03:05)
The One with the Stoned Guy - S1-E15
Continuity mistake: At the end of the episode when everyone is comforting Monica, Ross has his hand on her shoulder. In the next shot it is above his knee as he stands up. (00:20:05)
The One with the Stoned Guy - S1-E15
Continuity mistake: When Monica asks for the gummy bears near the end, she has her hands by her side. As the camera changes, a hand is now visible raised that should have been visible before. (00:20:00)
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