When Five-0 heads to the Ward Center, Kono is specifically told to have HPD secure all streets surrounding the area. However, when McGarrett is chasing the car, no HPD roadblocks can be shown blocking the streets.
At the end of the episode, after Danny pulls the trigger to kill Mateo Reyes, a sound of a casing hitting the floor is heard, but Danny is using a revolver (what appears to be a .357 Magnum), which keeps the expended cases in the cylinder.