Continuity mistake: Robin says in this episode that she never played team sports and was always a loner. However in a later episode, (The Prom episode) she mentions she missed her prom due to field hockey nationals.
Continuity mistake: When the Hula girl realises the penguin is Barney she holds her hands out and walks off. Camera cuts and her hands are on her hips. (00:17:30)
Other mistake: In the credits, Jeremy Gabriel (Robin's new 'boyfriend') is shown as "Mark" but it is "Mike" throughout the episode.
Continuity mistake: Robin says that she doesn't like team sports, and so she only played tennis in high school. However, throughout the show, Robin often talks about playing hockey during school, which is a team sport.
Continuity mistake: When explaining why he has 2 costumes every year, the way Barney holds his drink changes instantly. (00:12:00)
Continuity mistake: When Barney arrives at the apartment in his Top Gun outfit, we see him hang his sunglasses off his collar twice without removing them in between. (00:05:45)
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)
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: At the bar, when Robin is telling the gang about Mike, Marshall's beer moves from in his hand to on the table between shots. Also, the amount of beer in the glass changes frequently depending on the camera angle.
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