Revealing mistake: When Anguirus makes his sacrificial charge against Gigan, the hand that is moving the Anguirus costume can be seen holding it.
Revealing mistake: During the iconic dojo brawl scene, Bruce Lee at one point picks up two men and whirls them around. It's obvious in the wide shot that they are just dummies.
Revealing mistake: Louise kills the werewolf by firing three "blessed" bullets at him. But the third time she fires, the revolver doesn't revolve: the chamber remains stationary.
Revealing mistake: When Itto is battling the group of male ninja in the forest there is a moment when two ninjas throw chains towards Itto and in the close-up shot of the two chains flying at Itto the wires attached to the ends, guiding them, are visible. (00:33:55)
Revealing mistake: At the beginning of the film O-Yuki is fighting the men in the forest and kills them one by one. When she kills the last one there is a close-up shot of her dagger entering his rib area and blood sprays out. However, if you pay close attention you can see the blood sprays out of his sleeve (presumably there is a device in there), not his torso. (00:01:18)
Revealing mistake: When Shaft fights the bad guys disguised as flower delivery men, both die with their blood packs that explode triggered by visible pyrotechnics - kinda odd to shoot a guy and see literally flames burst out from his chest or back before any blood comes out. (00:48:50)