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.
Suggested correction: Throughout the movie Braden (as a ninja) has many instances where someone close up was distracted for only a second, only to look back and see he'd disappeared. This is especially true in the final rooftop fight with Cho. So it would be possible for him to be undetected from a distance in the scene where you're talking about. I also just watched this scene, and Cifano and his men are NOT looking in the direction of the informant but about to enter a vehicle when the star hits. They turn around and see him fall into the fountain. It makes sense that they wouldn't see Braden.