Continuity: The level of beer in Fin's glass on his first trip to the bar.
Continuity: Olivia's knees when she's lounging on the couch during the "Have you ever been in love?" scene.
Continuity: Near the beginning of the film, Olivia's shirt has a small hole right in the middle of the front. The fabric is undamaged in subsequent scenes.
Revealing mistakes: When Finn is at the grocery checkout, the cashier's register display says that the lane is closed instead of displaying the price.
Continuity: When Fin and Joe spend the night at Olivia's, the towel she brings to Fin and places at the foot of the bed disappears in the next shot.
Continuity: When Joe is making lunch for Fin and Olivia, the meat has grill marks, even though it's being fried with onions in a pan.
Continuity: When Fin picks up the groceries for Olivia, he has his bag on his shoulder. The bag is not there when he delivers the groceries, but it returns after he has left Olivia's house.
Continuity: Following the scene where Olivia returns home from the hospital, there is a brief shot of Fin and Olivia watching the sunset from her dock. This shot is in fact taken from an earlier scene where Fin and Olivia had a conversation on the dock as they are wearing the same clothing.
Factual errors: Fin pulls out a library card from a book that Olivia had checked out in her name. In the old library card/check system the card would have been kept at the library to keep track of who had checked it. It would not have been placed back in the book and then released to check out.