The One with the Blackout - S1-E7
Audio problem: When Phoebe is counting down to the last candle burning out you can see Joey blowing out the candle, but the sound of his blow is only heard a second later after he sits back. (00:22:50)
The One Where Nana Dies Twice - S1-E8
Continuity mistake: In this episode, Rachel tells Chandler that she thought he was gay until he spent Phoebe's entire birthday party talking to her breasts. But at this point since Rachel joined the group, Phoebe hasn't had a birthday yet; that occurs some episodes later, in "The One With Two Parts." (00:02:00)
The One Where Nana Dies Twice - S1-E8
Visible crew/equipment: When Monica and Ross meet up with their parents and their nana, a boom mic is visible at the top of the screen. (00:04:20)
The One Where Nana Dies Twice - S1-E8
Continuity mistake: When Ross and Monica are visiting Nana, Ross has his hand on Monica's shoulder. In the next shot it is gone. (00:05:05)
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The One Where Nana Dies Twice - S1-E8
Continuity mistake: In Central Perk, Joey says "So, Chandler looks gay huh?" When he does his arms are not crossed. Camera cuts and they are. (00:08:30)
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The One Where Nana Dies Twice - S1-E8
Continuity mistake: When Monica is talking to her dad at the table, the way he holds the magazine changes between shots. (00:08:50)
The One Where Nana Dies Twice - S1-E8
Other mistake: When Ross is helping choose a dress and shoes for Nana to wear, he is behind the chest of drawers in the cupboard. He looks in a shoebox and finds lots of pink sweet'n low packets, then pulls down another box and lots of packets fall down on him. However, it is obvious that someone is above him showering the packets down, as they are coming from directly above him, not from on top of the door. (00:12:35)
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The One Where Nana Dies Twice - S1-E8
Continuity mistake: When Joey shows Chandler the TV in his pocket, at first he takes in out and is holding it in one hand. In the next shot, he is holding it in both hands. (00:14:00)
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The One Where Nana Dies Twice - S1-E8
Continuity mistake: When Ross falls into the grave he ends up with a massive mud patch on his knee. He turns over and it's gone. (00:14:30)
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The One Where Nana Dies Twice - S1-E8
Continuity mistake: At the funeral, Judy says to Monica that Nana would have hated this [the funeral]. When she does, Monica's arm changes position between shots. (00:18:50)
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The One Where Nana Dies Twice - S1-E8
Visible crew/equipment: When the scene cuts from Joey and Mr. Geller watching the game, to several people watching the game, a boom mic is visible at the top of the screen and the camera tilts slightly. (00:19:00)
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The One Where Nana Dies Twice - S1-E8
Continuity mistake: Just before the group of guys at the funeral shout about the football, there is a glass of wine next to Monica's mother which is about 1/3 full. After a brief cut away, the next shot shows the glass is almost empty. (00:19:05)
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The One Where Nana Dies Twice - S1-E8
Continuity mistake: When Rach asks who the naked picture is of, the way she holds it changes between shots. (00:21:10)
The One Where Underdog Gets Away - S1-E9
Continuity mistake: When Rachel serves Joey coffee after he comes into Central Perk wearing make up, she puts the cup down on the far left hand side of the table. As Joey picks it up, it has moved to the far right hand side between shots. (00:02:45)
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The One Where Underdog Gets Away - S1-E9
Continuity mistake: When Rachel gets her mail off Monica she puts it down on the couch and picks up a sealed envelope. The camera cuts and the envelope is now open with no time to open it. (00:07:25)
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The One Where Underdog Gets Away - S1-E9
Visible crew/equipment: When Monica shuts the TV off while watching skiing, there is a closeup of the screen as it goes blank. You can see reflected in the blank screen an image of a man in a long sleeved shirt and tie, who does not correspond to any of the characters in the room. (00:08:00)
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The One Where Underdog Gets Away - S1-E9
Visible crew/equipment: When Joey walks into Central Perk after the VD poster montage, a tape marker is visible on the floor behind Chandlers spot on the sofa. (00:10:40)
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The One Where Underdog Gets Away - S1-E9
Continuity mistake: When Rachel turns up with her tickets, Chandler has his hand on his hip. As Rachel walks off however, his arm is behind her. (00:12:00)
The One Where Underdog Gets Away - S1-E9
Continuity mistake: Chandler is able to get into Monica's apartment to tell everyone that Underdog got away, but later when Rachel closes the door it is now locked. We can see the door as each person is leaving and nobody does anything which could be construed as locking the door before it closes. It's been often demonstrated in the show that the door doesn't lock automatically. (00:13:20)
The One Where Underdog Gets Away - S1-E9
Visible crew/equipment: When Chandler runs into the apartment to say Underdog has gotten away, a crew member can be seen reflected in the sun shaped mirror behind him walking through the back of the shot. It can't have been Rachel, Monica, Phoebe or Joey because Joey is sitting down and Rachel, Monica and Phoebe are nowhere near the mirror. (00:14:05)