Continuity mistake: When the guys are at the bar before going to the awards show, we see Marshall raise his beer to his mouth twice from different angles, without ever lowering it. Also, the amount of beer in his glass changes instantly between the shots. (00:03:30)
Nothing Good Happens After 2 A.M. - S1-E18
Continuity mistake: In the classroom scene, the girl with the black dress with green sleeves keeps changing position between shots. Her arms are sometimes folded, sometimes flat on the table, and sometimes she is leaning on her elbows. (00:01:40)
Continuity mistake: The morning after The Wedding, when Lily is talking about throwing the bouquet, the mug in Marshall's hand changes position, vanishes and then reappears instantly between shots. (00:05:20)
Continuity mistake: In the opening scene at the apartment, the mug that Ted is holding keeps changing positions in his lap between shots. Sometimes it is tucked behind the leg nearest the camera, whilst in other shots it is sat on top of that leg.
Continuity mistake: When Lily is making the layered salad, in some shots the layers are defined, but in others there is much more mayonnaise running between the layers. (00:07:30)
Okay Awesome - S1-E5
Continuity mistake: When they first arrive at the club we see Barney, in close up, undo some of his top shirt buttons. A few seconds later, he is seen in the background with his shirt buttoned. (00:05:30)
Okay Awesome - S1-E5
Continuity mistake: When the bartender holds up the napkin with the price of the drinks on it, he is holding it straight. The shot cuts to the view from behind, and the napkin is now held at a clear angle. (00:08:50)
Continuity mistake: At dinner, Robin starts eating the ice cream sundae and knocks the cherry off the top. In the next scene, when she passes the sundae to Mike, the cherry is back neatly on top and the sundae looks untouched. (00:12:50 - 00:13:30)
Continuity mistake: When Barney is at the apartment in his Top Gun costume, the position his helmet is in on the coffee table changes between shots. Sometimes the front of the helmet faces the camera, at other times it is sideways. (00:06:00)
Matchmaker - S1-E7
Continuity mistake: In the final scene at the Matchmaker's office, the tub of Haagen Daaz on the desk turns around between shots. Sometimes the brand name is visible, but in other shots the logo is facing away from the camera. (00:20:00)
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.