Continuity mistake: When Ana and Christian are having sex on the dining room table, she drops Christian's pants below his butt. Scene cuts and Christian's back is shown, with his pants above his butt. Then cuts back and they're below again. (00:54:40 - 00:56:50)
Continuity mistake: When Jack calls Ana from Mia's phone, he makes his demands and throws Mia's phone in the water. Then from the bank Ana calls Jack on a cell phone.
Continuity mistake: When Anna is lying on the concrete and you hear Christian say, "Anna, breathe," she disappears while cops are arresting Jack.