The One With Joey's Porsche - S6-E5
Other mistake: Immediately after Joey walks in as Chandler is handling the baby, we see him staring and waving in a direction past the stage. (00:06:55)
The One Where Ross Hugs Rachel - S6-E2
Other mistake: When Monica's trying to evoke some kind of an emotional reaction from Rachel, who's polishing her toenails, there's a bottle of Cutex nail polish remover on the table with part of the brand name painted black, so it reads "Cu Ex" on the label.
The One Where Paul's The Man - S6-E22
Other mistake: There are two mistakes in the scene where Phoebe spots Joey's picture in the laundromat. For one thing, when Phoebe says "Oh, here it is", she is looking in the opposite direction of the picture. Also, when she says this, her mouth doesn't move at all. (00:16:10)
The One Where Ross Dates a Student - S6-E18
Other mistake: Ross' semester supposedly just ended, and he's handing in his grades. But the episode just before this one was about Valentine's Day, and the one immediately after this one is about spring break, so this episode is happening sometime between mid - February and March/April. It doesn't matter when the show was aired or produced; Valentine's day is still in February. There's no semester that ends at that time of the year, and NYU wasn't on the quarter system then.
Suggested correction: This episode (production code 225567) was produced before episode 17, "The One With Unagi", (production code 225568) and just aired out of order. So this episode happens before Valentine's Day.
The One With Mac & C.H.E.E.S.E. - S6-E20
Other mistake: When we see the chess board at Central Perk that Ross and Chandler are using, the black pawn in front of the black knight nearest the camera is missing, and from the arrangement of the white pieces, it cannot have been captured yet.
The One Where Ross Hugs Rachel - S6-E2
Other mistake: In this episode, Chandler says that "when it comes to sweets, [Joey] is surprisingly strict" and doesn't allow sweets around the house. Except that in Season Five, "The One With The Kips," we see that Joey leaves Rollo candies everywhere.
The One With The Proposal, part 1 - S6-E24
Other mistake: Joey bids on a Catalina 22 yacht, but the picture, and the yacht he and Rachel are on at the end, is a Catalina 18.
