Other mistake: When Anika falls to her death, as she lands, there's already a moderately-sized puddle of blood beneath her, which makes no sense, as she only just landed that instant. Then, when it cuts immediately to a wider shot about two seconds later, there is suddenly even more blood around her body.
Other mistake: When Sam and Tara first meet Gale outside, after Gale gets punched, pay attention to the multiple news crews behind her as they start arguing about Gale's book. Randomly, they go from paying attention and recording to suddenly all dispersing and packing up after the shot cuts to Sam and then back to Gale. This makes absolutely no sense. They're all involved in a very famous case; there's no reason every reporter there would suddenly start packing up in the five seconds they were offscreen.
Answer: I think this is more "trivia" than mistake. There's no error in a film taking place a bit further ahead in time than in its release date.
TonyPH