Continuity mistake: At the wedding reception, the groom burns the prenuptial agreement to the shock of many. Charity looks down at it in shock. The scene cuts, and she's instantly looking up at the groom.
Factual error: No matter how rich Emily's fiancé is, she wouldn't be out free "on appeal" and just allowed to go travelling off to Italy.
Plot hole: In the flashback recounting the events that led to the identity swap, Emily says her aunt was blackmailing her for 20 million dollars. The blackmail was based on Dante and Matteo's secret. It's never explained how on earth this person knew this hugely important secret that no one else but Emily and the two lovers was aware of, especially considering that Emily had no contact with her family at all.
Plot hole: Emily learned Italian during her youth in Rome, thanks to her time there and Dante Versano's tutoring. Considering that a good portion of the movie we don't deal with the real Emily but with another person impersonating her, it's unclear how this imposter could have learned the language and everything else about the family, given she certainly didn't have years to prepare and Emily's life as "Olivia" was not publicly known.
Other mistake: Considering who the culprit is and the fact that they were speaking to the victim at a distance just before shooting them, it's impossible for Charity to make it back to the party before Stephanie. While they could have run faster, it makes no sense for them to casually appear to the left area; they should either come from the right - the direction where the shots were fired - or we are supposed to believe they circled around passing behind the burning warehouse. Furthermore, the film's ending reveals that the murder was not premeditated, so Linda was not actively helping.
Continuity mistake: Portia takes an envelope from her purse, holding it between her index and middle fingers. Initially, the index finger is behind the envelope and the middle finger in front, but in the penultimate shot, they switch places, with the index finger now being the one fully visible to the camera. (01:53:30)
Continuity mistake: When the Trevi Fountain appears in the movie at the end, Blake Lively is sipping a drink, holding the glass in her right hand. The scene continues with a cut where she holds it in her left hand, and then, as she walks toward Elena Sofia Ricci, she has it in her right hand again. (01:51:40)
Continuity mistake: During the finale, Emily talks to her sister, trying to convince her to turn herself in by pretending to be her. During the conversation, Charity's fingers touch Hope's face in different positions depending on the shot. (01:48:30)
Continuity mistake: When Hope distracts Charity with a kiss, she's holding her arm at the wrist when Stephanie grabs the weapon, but higher up in the wide shot. (01:48:00)
Continuity mistake: When Charity guides her foster mother's gun to her forehead, her fingers are on Linda's hand in one shot, but on the gun barrel in the previous one. (01:46:10)
Continuity mistake: Emily's neck scarf is scrunched differently during the live scene depending on the shot - especially noticeable between the close-ups during Charity's live and the wider shots at the beginning and end of it, when it's poofier. (01:42:40)
Continuity mistake: During the live broadcast, Emily holds the phone with her right thumb at a consistent height in close-ups, which differs from her hand position in the other shots. (01:41:40)
Continuity mistake: When Charity tells Emily she can make her feel so good 'at the same time,' she moves Emily's arm to access her limp body more freely. Emily's hands have shifted position between shots. (01:39:00)
Continuity mistake: Stephanie has to stop the Vespa to barf. She's leaning on the railing in two different spots between shots - as you can tell by the bars. (01:33:00)
Continuity mistake: After being drugged, Stephanie fidgets in her chair—notice she's sitting in a slightly odd position, shifted entirely toward the left armrest. In the reverse shot, she moves her back and legs. When the camera returns to the previous angle, where she asks, 'Who's there?' her posture is unchanged as if she never moved. (01:26:05)
Continuity mistake: When Stephanie looks for her unlikely savior, Irene, Irene awkwardly approaches her before meeting an unfortunate fate. In this scene, the natural lighting changes depending on the shot—just look at Irene's bright fuchsia dress. (01:23:05)
Continuity mistake: The Neapolitan waitress approaches Stephanie and says she was sent by Irene. In the close-ups of Anna Kendrick, her hair alternately covers or reveals her left shoulder. (01:15:00)
Continuity mistake: After the police confiscate her phone and passport, Stephanie lies in a stupor, staring at the ceiling. Her hair is scattered differently across the pillow between shots. (01:14:50)
Continuity mistake: When Aunt Linda holds Emily's arm to provide an alibi, her arm is either raised or lowered depending on the shot. Similarly, nearly a minute later, when Portia turns to Stephanie, Linda is either holding Emily's arm or not. (01:07:40)
Continuity mistake: At the evening party, watch Alessandro the bartender prepare Stephanie's martini; he places the glass on the counter and removes his hand, but in the next shot, his arm is back down on the counter. (01:05:20)
