Sweet Taste of Liberty - S1-E3
Revealing mistake: Barney tells the cab driver to lock the doors, and he does. We then see Ted trying to open the door and you can hear the taxi is still driving by the engine noise. However, the scenery outside the windows has stopped moving. (00:01:50)
Sweet Taste of Liberty - S1-E3
Continuity mistake: After Lily takes off her ring in the bar, she is seen in a later shot with the ring on her left hand.
Sweet Taste of Liberty - S1-E3
Continuity mistake: When Marshall is on the phone to Barney, the green highlighter jumps back and forth from on the desk to on top of the open book.
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