When Vincent walks up and admires the Christmas ornaments he sees on the table, Tori has open paint containers there, a paintbrush in one hand, and an ornament in the other that she is working on. He comments that his mother would enjoy an ornament. Tori hands him the one she is painting which would be wet, rather than a dry one from the table. No paint appears on his hands.
Members of the Vienna Philharmonic are selected from the orchestra of the Vienna State Opera, and only after several years of playing for the opera orchestra. An outsider, such as the main character Jess, would not be offered an audition with the Philharmonic.
The movie states that Olson family had been living in Vienna for about a year and that the deceased mother was Viennese. Yet, early in the movie, Julian, the middle child is using a phrase book to learn how to say 'goodbye' in German. Surely someone who has lived in Vienna for that long would have already learned how to say goodbye in German.