When Mickey pounds the kitchen windows to threaten Francine, he repeats "I'm going to break the door with your face" at two different points, with the same inflections each time, revealing the line as recorded dialogue.
Near the end of the film, we see Francine get beaten brutally in the face. But when she is arrested a day later, there are hardly any bruises on her face at all.
The real Francine Hughes had four children, not three as depicted in the movie.