Factual error: Star shuriken, despite common misconception, are not inherently deadly weapons. They were mostly used for distraction, since their lack of a single weighted point makes their attack rather inefficient (although the weapon could be coated with poison). Although it is possible to hit an eye, it is very difficult to hit such a small target or scoring a sufficiently deep wound to penetrate to the brain with a star shuriken.
Plot hole: To murder Chifano's informant, Braden uses a throwing star. But there is one thing which makes this scene illogical: Braden is evidently not in his civilian suit, but in his ninja costume (the ninja suit's armsleeve is definetly on his arm). But since Chifano and the informant are looking in the same direction when the throwing star hits, and since a ninja costume would make Braden stick out like a sore thumb, it is VERY impropable that he'd escape the scene just like that.