The One Where Rachel's Sister Babysits - S10-E5
Continuity mistake: Rachel and her sister are in Rachel's room. When Rachel picks up Emma, Emma has nothing in her arms, but in the next shot when Rachel is holding her, she has a toy in her arms though she had no time to get one.
The One Where Rachel's Sister Babysits - S10-E5
Other mistake: Jennifer Aniston's tan mark from her wedding ring is especially visible in this episode. Most notably when she says "But Erin Brockovich had her own house."
The One Where Rachel's Sister Babysits - S10-E5
Continuity mistake: While everyone is booing Mike and Phoebe, the guy sitting behind Phoebe changes position in every shot.
The One Where Rachel's Sister Babysits - S10-E5
Continuity mistake: When Ross is looking at Emma in the coffee house he turns and looks at the guys on the couch and mouths the word "what." Then in the next shot he does it again.
The One With Ross's Grant - S10-E6
Continuity mistake: When Monica comes round to Phoebe's, Phoebe reminds her that she's got to clear out stuff. In this wide shot Monica has both hands by her sides, but when it cuts to her finishing saying "oh right", her right hand is now gripping her bag's strap. (00:05:00)
The One With Ross's Grant - S10-E6
Visible crew/equipment: When Dr.Hobart enters the meeting room to conduct the grant interviews, markers can be seen on the floor around the first chair's wheels as well as in front of the table. (00:12:25)
The One With Ross's Grant - S10-E6
Visible crew/equipment: When Joey turns the video off, the end of the set is visible in the TV. (00:15:10)
The One With Ross's Grant - S10-E6
Continuity mistake: When Aisha Tyler and Greg Kinnear put one hand on Ross's face, they bring those hands together and they interlock fingers, then the camera changes positions and they interlock fingers again. (00:22:20)
The One With Ross's Grant - S10-E6
Continuity mistake: When Charlie and Benjamin are at the restaurant, Benjamin says "I can't believe you chose this restaurant. You remember that night?" To which Charlie replies "I can't believe they let us back in here." However in "The One With The Fertility Test" Charlie has never been to New York before.
The One With Ross's Grant - S10-E6
Continuity mistake: After Joey puts the video in the player, it's clear the video doesn't go all the way in, and even starts to eject itself. The shot cuts, and without him making any moves to replace the tape, it plays fine.
The One With Ross's Grant - S10-E6
Continuity mistake: When Phoebe tells Rachel and Monica that Mike lets her keep her box of hair, Rachel's chopsticks are down, by the plate. In the next shot, she's holding them close to her mouth.
The One With The Home Study - S10-E7
Other mistake: In the opening scene Chandler smiles at Ross' joke while playing with the ball in his hands. Later on in the scene Ross cracks another joke and the exact same scene of Chandler smiling and fiddling with the ball is repeated. (00:00:40 - 00:01:10)
The One With The Home Study - S10-E7
Continuity mistake: When Phoebe and Mike first donate the money to the children, the way the man is holding the cheque changes depending on the shot. (00:03:15)
The One With The Home Study - S10-E7
Continuity mistake: When Mike says "I am going to make this decision for us. What do you think we should do?" he is holding the check. The very next shot shows the charity worker taking the check off the desk and giving it back even though Mike never put it down. (00:20:35)
The One With The Home Study - S10-E7
Visible crew/equipment: After the opening credits, in the first shot when Joey walks into Monica and Chandler's apartment, the shadow of filming equipment can be seen moving at the left side of the screen. (Widescreen version).
The One With The Home Study - S10-E7
Audio problem: While the adoption social worker, Laura, is interviewing Monica and Chandler, Monica mentions to her that she's welcome to look under any of the furniture where she won't find cigarettes or porn, and then it cuts to Laura's close-up as we hear her say, "Well, actually before we look around," but her mouth is not saying those words.
The One With The Home Study - S10-E7
Continuity mistake: When Ross and Rachel are pushing Emma on the swing, the legs of Emma's pants change position several times between shots. At first they are pulled up with her legs exposed, then they are down further, and in the last shot when Ross gets kicked, they are pulled up again.
The One With The Home Study - S10-E7
Continuity mistake: When Chandler kisses Monica before letting the social worker in, she puts her hand on his arm. The camera cuts to her and she says "Tongue, really?" but her hand is by her side now. The camera cuts back to Chandler and both her hands are now out in front of her.
The One With The Late Thanksgiving - S10-E8
Continuity mistake: When Rachel and Phoebe are talking in the Baby Beauty Contest and Rachel is holding Emma, Emma's head instantly changes position between shots several times, often going through 180 degrees. Clearly they couldn't get her to do the scene in one take and therefore the editing suffers. (00:07:05)
The One With The Late Thanksgiving - S10-E8
Continuity mistake: The food/sauce stain Joey gets on his shirt (after running into the cart) changes between shots. (00:20:50)
Answer: Usually by the seventh night of Hanukkah you don't know what to get the other person, and you will probably resort to getting the other person something insignificant. Chandler is basically saying that the pen is a stupid gift.