Revealing mistake: When Amy and Ben are sitting on the stairs talking and she asks him if he was freaked out about her saying that they could move in together, if you look in between the bottom stair rails, there is a man in a yellow shirt jumping up and down waving his arms.
Revealing mistake: In the pool scene after Ben saves Amy, Ben turns to Swimfan. If you look closely at Swimfans feet you can see she is wading in the pool.
Revealing mistake: When Ben looks at the picture of Madison, it shows her hands supposedly covering her breasts. But you can see the flesh colored cloth that's protecting her modesty.