Character mistake: Tina Fey fumbles her line and has to start it again. The original line should have been "How long do you think you're going to get away with this? Hazel or Jenna will know we're missing." Instead the second part of the line is "Henna or Jay; Hazel or Jenna will know we're missing!" (00:04:05)
I Can't Make You Love Hannah If You Don't - S1-E4
Character mistake: When Olivia turns up at Jackson's house, she says, "That was my Saturday afternoon. This is my Saturday night!" which indicates it is the same day. But when Cooper arrives, he says, "Sorry for blowing off at you yesterday," which means another day has passed. However, at the Hannah concert, it is the same day all the while, so Cooper had got his days wrong.
Character mistake: When Betty and Daniel takes Oshie to the White Tassel, as they are walking in, Daniel asks Betty if she is sure that they do not have anything over $5, Betty smiles and agrees. However, when there is an establishing shot of the restaurant, it states in the window that there is something for $9.99.
God Is in the Details - S2-E10
Character mistake: When Diane quotes the scripture, she says "Revelations." However, it's just "Revelation." Someone as smart as her who has read the New Testament (or heard it quoted) would know the correct word.