Continuity mistake: When Lucy and Jack are walking along the river, a long shot shows them approaching a lamppost with a kissing couple. In the next shot, they pass the lamppost but there is no one there. They finally pass the couple at the next lamppost. (00:46:55)
Continuity mistake: When Lucy and Jack are moving the couch into Peter's apartment, Lucy gets bumped and falls into a table, knocking over a vase of flowers. (This table and vase are located directly below a mask on the wall.) Earlier in the film, when Lucy enters Peter's apartment for the first time (to feed the cat) we see her slowly entering the living room in the same area where she later falls - the mask is there, but the table and vase of flowers are not.