Continuity mistake: When Ross and Phoebe are in the bar and get on the pool table to start kissing, Ross moves the pool balls out of the way, but two remain. As Phoebe lies down, the 9 ball is next to her left shoulder. The shot cuts closer and it is the 13 ball, then cuts back and it's the 9 ball again. (00:19:40)
Continuity mistake: The beginning to series 7 takes place right after series 6 ended, basically Chandler has only just proposed to Monica. Yet Monica's hair is visibly different; at the end of series 6 she had no fringe and a center parting, now she has a fringe. Also Chandler, is visibly thinner, with a gaunt face due to losing 20 lbs in between the two series. Rachel also has had a hair cut, her long extensions have been removed and she is back to her usual hair length.
Continuity mistake: Rachel is said to be the youngest in the group as they reminisce about their 30th birthdays, however this episode reveals that almost all of the characters ages have been inconsistent throughout the series. In Season 1, Joey is said to be 25. In Season 2, he says he is 28. In S7 E1, he says he is 31. In Season 1, Monica is said to be 26. In Season 7, she should therefore be at least 32. Rachel graduated high school with Monica, so she should also be about 32 in S7, not just turning 30. She would have been 26 in S1. But, in Season 4, she refers to herself as a "28-year-old cheerleader". Based on Season 1, Joey should actually be the youngest member of the group, not Rachel.
Continuity mistake: When Phoebe is in the coffee house talking to her father and pretending to be the executor of her grandmother's will, after she says "lipstick and a daughter, big day for you" she folds her papers in half, but in the next shot they are unfolded and she then folds them again. (00:15:15)
Continuity mistake: After Marcel has escaped from the basement, he is seen eating a banana as a pair of arms reach out to grab him. These arms are supposed to belong to Mr Heckles, their weird neighbour, however the arms clearly belong to a young, large and hair free woman. (00:16:10)
Continuity mistake: Monica and Chandler are piling their dinner plates with food while arranging to meet for a second quickie. Chandler's plate is stacked with various items when he agrees to meet Monica in the cellar, but when he tosses his plate back onto the table to rush off without eating anything, the plate is nearly empty. (00:04:45)
Continuity mistake: When Rachel is talking with Phoebe about Paolo,. she unrolls some kitchen paper and uses it as a tissue. Initially she's holding two torn halves attached to the roll, then when saying "He's a pig" it goes to a whole sheet not attached to any others, then when she sits down it's a whole sheet attached to the roll again. Plus when Phoebe sits too, in some shots the paper is on the table, in others it's not. (00:15:20)
Continuity mistake: When Monica takes off her belt and throws it onto the couch, it lands on Rachel's arm. Throughout the scene, between shots of Rachel and Monica talking, the belt constantly disappears, reappears and changes position without Rachel ever touching it. (00:05:25)
Continuity mistake: We've seen the arrangement of Joey and Chandler's bathroom in two previous episodes (1x3, The One with the Thumb, and 1x12, The One with the Dozen Lasagnas) with the sink opposite the bathroom door. In this episode the sink is relocated and the bath/shower is now opposite the bathroom door, for the rest of the series.
Continuity mistake: At the end of this episode, Ross opens the door of Rachel's room, says "Hi", and then closes it. However, in the next episode (The One With The Jellyfish), this scene is shown again and changed: Ross opens the door of Rachel's room, says "Hi", and doesn't close it - he talks with Rachel and Bonnie with the door open. (00:21:05)
Continuity mistake: When Rachel wakes up Emma during a nap, against Phoebe's advice, there is a shot of Emma in the cot. She is wearing a plain pink hat, but in the next shot, when Rachel lifts her out of the cot, she is wearing a white hat with what looks like little flowers on it. (00:05:55)
Continuity mistake: Rachel is talking to Joey in his apartment after waking up the next morning, looking messy and rumpled. As she talks, her bra strap slips down her arm. In one shot (as she says "I'm a horrible person"), the strap is all the way down her arm and then in the next shot it is tucked under her shirt. (00:10:00)
Continuity mistake: Towards the end of the episode, Ross and Chandler come into Monica's apartment and Ross asks where Rachel is. Watch the objects in Monica's hands, in the shot from behind she puts them on the table, and then does it again in the shot from the front. (00:24:00)