Continuity mistake: When Robin is talking to her boss about his dog, the pens and pencils in the holder on his desk change depending on the camera angle.
Continuity mistake: After Natalie throws spaghetti at Ted, the amount and position of the spaghetti pieces changes instantly between shots.
Continuity mistake: When the gang are discussing what Ted should say to break up with Natalie, the amount of beer in Marshall's glass goes up and down between shots.
Continuity mistake: When Ted is talking about getting a blessing from a pimp, Barney's drink just disappears from the table. (00:03:35)
Nothing Good Happens After 2 A.M. - S1-E18
Continuity mistake: When Robyn is leaving at the start, the dogs change place instantly. Note the Dalmatian. (00:01:30)
The Pineapple Incident - S1-E10
Continuity mistake: When Trudy takes Ted's phone she grabs it with 2 hands. Camera cuts and now she has one hand on her face. (00:17:35)
Matchmaker - S1-E7
Continuity mistake: In the opening scene at the bar, when Ted and Barney are discussing the idea of going to visit a Matchmaker, Ted's beer glass suddenly goes from being about a quarter full, to being nearly three-quarters full. (00:02:20)
Continuity mistake: The foam on top of the drinks Barney puts down at the start changes drastically between shots. (00:01:50)
Okay Awesome - S1-E5
Continuity mistake: Ted asks if he had a stroke at the start of the episode and puts his hand to his chest. Camera cuts and his hand has swapped from his right to his left on his chest. (00:00:35)
Okay Awesome - S1-E5
Continuity mistake: In the opening scene at the bar, Ted's beer bottle moves from in his hand on his lap to on the table between shots. (00:00:30)
Continuity mistake: When breaking up with Natalie, her hands are constantly changing position between instant cuts. (00:18:30)
Continuity mistake: When Barney is scoping the apartment, his hands are next to his temples. As the shot changes to a wider shot, they are now much further away from his temple. (00:08:05)
Continuity mistake: When Barney is explaining about there always being 1 girl who doesn't know who's party it is, his hand is sudden;y outstretched or by his side depending on the shot. (00:08:00)
Continuity mistake: Barney tells Lily that she's rubbing his leg. When he does, a wine glass suddenly appears in Lily's hand. (00:03:20)
Continuity mistake: When Ted mentions having a party, Marshall's hand goes from on his beer to on his chin instantly. (00:03:10)
Continuity mistake: In the pilot episode we see the Son and Daughter listening to the start of the story on how Ted met their mother. In the final episode of the show it's revealed that the whole story has taken place in one sitting. However, the clothes the kids are wearing and the items around them are different in the pilot episode to every other episode. The sofa is a different design, the cushions appear etc. (00:00:45)
Chosen answer: She was finally shown at the very end of the last episode of season 8, continuing into season 9. The actor's name is Cristin Milioti: http://www.imdb.com/name/nm2129662/.
Knever