Continuity mistake: During the entry scene, the ninja jump through a small door in a cliff-face into the water below. They come through the door one at a time, but the first two land in the water together.
Revealing mistake: When Jen Moo returns for Uncle Foo and Ching, and Chee makes him jump into the pool filled with flaming oil, it is quite obvious that only part of the surface was actually flammable. If the pool was filled entirely with oil, the entire surface would be ablaze, but there was water in it to enable the stuntman to survive.
Continuity mistake: During the intro scenes, eight ninja run the parcour. When they scale the wall with their hand-claws, there are suddenly just six, and when they run down the steps in the forest, they suddenly number eight again.
Deliberate mistake: When Jen Moo and Ching fling back the fire bombs thrown by Leong Kit, they set the rear ends of his students on fire. But since they were all standing facing front and dispersed around the altar, they would be most unlikely to be hit that accurately in that particular place.
Plot hole: When Ching and Jen Moo are confronted by the God Skills Society at the Sun Family Temple, there are three disciples appearing behind the master. But only two of then (the long-haired man, and then the monk) are seen entering the fight; the third one suddenly appears as a yellow-clad corpse at the entrance stairs as Ching fights the long-haired man.
Continuity mistake: When Leong Kit throws his ball and Jen Moo attaches his explosive charge, he has to bend back to do the job, since the ball bounces back low. But Leong Kit catches it at chest level, whereas - judging by the angle the ball was returning - the ball should be headed for his groin.
Continuity mistake: In the final scene when Chee makes his remark about feminity being the best weapon, Ching and Jen Moo simultaneously execute a flying kick against him. But when Chee starts talking, both fighters are just about ten feet away from him; but their running starts come from a longer distance - at no point do they step backwards.
Continuity mistake: When Ching employs the black-and-white sheet, in some scenes he spreads it across his back before he blends in with the walls. But he gets ready to ambush Jen Moo holding the sheet spread out on his front side without revealing himself while changing hold and position.
Continuity mistake: Leong Kit's son ties a headband around his hair before he starts his demonstration at the restaurant. In the first shot, his hair is held tight by the band, but when he starts his exercises, it suddenly overlaps the band.
Revealing mistake: When the God Skills Society display their skills at the restaurant, a portable bench gets chopped through by a sword. But the corner that gets cut off hangs only on by a small splinter, and there is a seam already visible (the shot is really short, though, so you must look closely).
Factual error: When the God Skills Society disciples build the altar in front of Ching's family temple, they just cover the horizontal ladder-like part with only a cloth strip and then place two candles and a heavy bowl with incense sticks on top without making the cloth sag between the rungs or the items fall off, since there is no solid board underneath.
Revealing mistake: There are two scenes where the same shot - Jen Moo running through a patch of light forest - has been used. One: in the beginning, when Jen Moo rushes to his ambush site; and two: after he has tricked Ching on his house boat.
Continuity mistake: When Jen Moo darkens the trap room, Ching drops the last lamp into a vase to prevent it from being extinguished. But in that shot, he grabs the lamp, raises his arm, the light in his hand just winks out, and the vase suddenly lights up. A falling lamp is nowhere in sight.
Revealing mistake: When Ching uses the two-colored cloth to trick Jen Moo,the film makers frequently made use of a white-painted wooden screen. Easy to see in the two instances when Ching sneaks up on Jen Moo or when the latter spots the holes he's burned into the cloth.
Deliberate mistake: For most part, the actors (in the original version) talk in their native languages. But in many instances, the subtitles in the English versions have a different meaning than the spoken words. That is what I noticed in the Japanese dialogues, and most likely the Cantonese parts have been thus 'mistreated' as well.