Because the events are told in a nonlinear way:
The story is told in an unusual, non linear manner, with
flash-forwards to interviews with people involved in the robbery a la
Warren Beatty’s “Reds” (1981).
Nonlinear narrative, disjointed narrative or disrupted narrative is a
narrative technique, sometimes used in literature, film, hypertext
websites and other narratives, where events are portrayed, for example
out of chronological order, or in other ways where the narrative does
not follow the direct causality pattern of the events featured, such
as parallel distinctive plot lines, dream immersions or narrating
another story inside the main plot-line. It is often used to mimic the
structure and recall of human memory, but has been applied for other
reasons as well.