CONTAINS SPOILERS. When Enrique Leyra gets shot in the back by Manuel during the Vampiro assault, he falls and you see a close up of his body where you can see the wounds in his back. A few moments later he is shown laying next to the fountain still, but has no wounds in his back at all.
In the final attack, Sgt. Contreras' rifle has no sights of any sort. He is supposed to be a highly trained soldier, and they have just purchased high quality equipment. He also makes many highly accurate shots, which is impossible with no way to aim.
A scene where a mirror is punched. The mirror was broken before, but when broken again then break was moved, and the reflecting image was changed.