Continuity mistake: Lily and Marshall mention that they've been using the same toothbrush ever since they've been together, but in the 14th episode of the 1st season, "Zip, Zip, Zip", Marshall and Lily are simultaneously brushing their teeth with a tooth brush each (before Ted and Victoria get home). (00:05:05)
Continuity mistake: When Rachel finds out that Ross and Julie are getting a cat, watch Rachel's neck. When she says "together?" she's not wearing a necklace; cut to Ross and Julie for a fraction of a second, then when it cuts back to Rachel saying "both of you?" she's suddenly wearing a necklace. It then disappears again when she says "isn't that just lovely?" hanging off the side of the tray she's holding. (00:05:15)
Continuity mistake: When Kitty comes downstairs to give the gang cookies, she tells Eric that she picked out an outfit for him to wear on career day. He then turns and mouths the words "Help me." In the next shot you can see Jackie sitting on Kelso's lap when in the previous episode, she broke up with him. In the next shot she is standing behind him. (00:01:00)
Continuity mistake: It is the evidentiary hearing, all characters are put on the witness stand so you get to see what all of them are wearing. The trial starts the next day and lasts at least three days, but when they are in court at the end of the trial for the reading of the verdict for the gravedigger they all have the exact same outfits on as the day of the evidentiary hearing.
Continuity mistake: Samantha and Carrie are hanging Carrie's poster in her apartment. In one shot, the whole poster is pinned to the wall and in the next shot, the bottom left part of the poster is curling up. After another shot of Samantha, the poster is pinned perfectly to the wall again.
Continuity mistake: Brooke and Ridge have known each other for at least 3 years when Rick is born. Yet when Rick is 16 Brooke and Ridge talk about how it's been ten years since they met. Even given soap opera children's amazing ability to grow it's a huge mistake that they say they've only known each other ten years when it's at least nineteen.
Continuity mistake: When Catherine enters the precinct station, the desk sergeant places a small white file box on the counter. There's nothing else sitting next to this, but when the shot reverses, a tall black police radio with an antenna sticking up has appeared there. (00:16:10)