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.
