The plot of this film (which is "a retelling" of Shakespeare's Romeo and Juliet) is built on the premise that Rosaline was dumped by Romeo and she wants him back. This is not the case in the source material. In Shakespeare's play, it is Rosaline who rejects Romeo, as she does not reciprocate his love, and has instead taken a vow of chastity. (Act 1 Scene 1)
In a camera switch, at the Montague estate when Rosaline and Dario is hiding from the guards, the torch which Dario carries is mysteriously vanished.
The closest significant body of water, Lake Garda, is 35 kilometers (nearly 22 miles) away from Verona, which is too far for the characters to move between the docks and the city as easily as in the movie.
Dario is heard speaking French almost fluently but makes a beginner's mistake when he mispronounces "Femme" (woman) 'Fehm' instead of 'Fahm'.