It wouldn't have worked well in the film, but it worked excellently in the book. Readers usually can detect when a death or something sinister will occur soon. Doing it in flashback style meant that the statement came as a sudden shock, the reader would be like "huh? what? when? how? why? er...?" and then there is plenty of time to explain how it happens. Other writers often do it normally, and it's just as effective, but when I read the Sicilian, having never seen the film, the similarly styled flashback events really worked well.