Continuity mistake: When the ninja shows his super-strength by lifting the golf cart, his left-hand keeps changing position at the back of the vehicle. (00:04:40)
Revealing mistake: The evil ninja blows a dart inside the barrel of a gun making it explode when the bodyguard fires. Forgetting the fact that the movement is unnatural and patently phony since the film is reversed, the dart also fully 'disappears' inside the gun and yet again when we see the guy about to shoot there's an inch-long of dart sticking out of the gun. (00:04:20)
Continuity mistake: Throughout the whole first fight scene the natural light is obviously different between shots. It is already noticeable at the very beginning when the golfer stands by the cart with much more sun on him in close-ups, but also even more obvious when the ninja downs the first opponent that falls in the shade but is lying fully in the sun as his partner assaults the not-so-elusive killer. (00:03:30)
Continuity mistake: The ninja suits up during the opening credits; he reaches inside the weapon stash with his left hand to pick the shurikens, but in the following shot he draws back his right hand. (00:02:40)
Continuity mistake: In a moment during the fight scene between Ninja Christie and the cop playing billiards, she kicks him into a wall. His hand is raised in one shot but not in the next. (00:38:20)
Continuity mistake: In the sequence where Hanjuro crashes the helicopter, the pilot disappears and reappears at random. (00:09:15)
Suggested correction: Actually no; he's still there even in the camera angle the second screenshot is from; the knee of the policeman that is fighting Hanjuro covers his head, and then the seat makes it impossible to see him again. You may have to slo-mo to spot it, but he's visible at the beginning of the shot.
Continuity mistake: During the golf course opening scene, a motorcycle cop gets kicked to the ground by the ninja swinging from a grappling hook. In the next shot, the cop somehow falls into the water hazard along with his motorcycle. (00:07:28)
Other mistake: Christie starts killing people at the funeral, and those in attendance start running away. When it shows a couple hiding behind a car, the woman is corpsing at best, the man is flat-out laughing. (01:05:15)
Other mistake: When the ninja slices at point-blank the obese cop in the pool room, the make-up used is a single strip of blood. Obviously they wouldn't show a graphic dismemberment or decapitation, but the man here practically dies from a cut on the cheek. Men do more harm to themselves shaving. (00:38:50)
Other mistake: When the two caucasian heroes smile back at their new asian friend at the end of the movie, you can see that Lucinda Dickey's hair looks somewhat blacker and with a thicker front bang. She's wearing a wig, since it was a later reshoot, and she had already cut her hair short for her role in Breakin' (which was shot later despite ending up being released before this movie). (01:29:00)
Other mistake: During the final fight, the Black Ninja (which confusingly enough is the one wearing green, and the ninja in black is the good guy) in some shots wears pale white cadaver makeup around the eyes, and in other does not. His fingers are also constantly of a healthy color.
Other mistake: During the movie it had been made clear that Christie would pick up bruises and black spots from the fights, and they wouldn't heal in minutes. However, Lucinda Dickey's face is spotless when Jordan Bennett finds her at the temple, and she had a big shiner and cuts during the earlier scene at her house. (01:23:20)