Intervention - S4-E4
Continuity mistake: In this episode, both Ted and Marshall mention that Lucy, Stella's daughter, is 7 years old, when in the previous season (13th episode of 3rd season, Ten Sessions) Stella states: "I have a daughter. Her name is Lucy, she's 8." Did she grow younger?
Intervention - S4-E4
Continuity mistake: After the gang gets to the bar around the end of the episode, Ted starts his speech about how they all need to move on. As he moves over to the booth, he tells the people sitting there to get out. You can see that the girl takes her phone with her, and there is no other phone anywhere on the table. A few seconds later, she comes back saying that she left her phone, and now the phone is visible on the table. (00:19:25)
Continuity mistake: Robin says she never played any team sports in 1-6 "Slutty Pumpkin". But in this episode she talks about her relationship with her father, being on a hockey team that won a championship and she made out with her teammate.
Continuity mistake: During the scene back in college, when Marshall and Lily are listening to Dr. X's show, at the first shot of the radio, you can see some popcorn there already, although Marshall has not thrown any, yet. Even if you claim he's been throwing constantly, a few shots later they vanish, and reappear.
Intervention - S4-E4
Continuity mistake: In this episode we see that Barney punched a hole in the wall next to the door because Ted broke apart a girl fight. It is supposed to be under the calendar on the right side of the door. It is also said that Ted and Robin were dating at this time. But earlier, in the episode "Wait For It..." (3-1) We see Ted going through his break up phase after Robin. One of the phases is painting the apartment, and there is no hole.
The Best Burger in New York - S4-E2
Continuity mistake: When Ted picks up his burger it already has a bite taken out of it, then in the next shot the burger is whole again. (00:20:09)
Continuity mistake: When they call Barney to find out if he succeeded with The Naked Man, the girl answers the phone. In that shot Barney's tie is curled up next to the shirt, but in the next shot, the tie lies on the shirt. (00:19:00)
Continuity mistake: When Lily is making her list she takes the lid off the pen twice. (00:09:00)
Suggested correction: Depending on the location settings on his laptop, they could be giving a false reading. My laptop shows I'm in Cardiff Wales while in fact I'm nowhere near.
Ssiscool ★
The show was actually filmed on a film set in Los Angeles which is probably why the laptop says Los Angeles as the current location. This most probably slipped past the editing crew.