Continuity mistake: When Braden sets out to kill Caifano's brother, he wears a business suit and carries a small bag as he enters the restrooms. But when he confronts his victim, he carries a ninja-to (ninja sword) in his sash. The sword is definetly too long to fit in the bag or under the suit, and I've never heard of dismantable combat swords.
Continuity mistake: The Masked Ninja (Braden) carries a lot of weapons which keep appearing and disappearing whilst he inflitrates Chifano's building; his spear-stick and a throwing axe (both relatively big - and therefore visible - weapons), for example, are both there whenever he needs them.
Continuity mistake: When Braden is confronted by Cho's mother, she throws a blade at him, which he catches and throws back, sticking it in her shoulder. She uses a blowgun and there are two shots of her with the blade in her shoulder and blood on her clothes from the wound. However, when she misses there is a shot of her using a smoke ball where there is nothing in her shoulder, nor is there any blood on her clothes.
Continuity mistake: The throwing stars which Braden uses to kill the one-eyed informant change from the time he throws them to the time they hit the guy. When Caifano picks up the body of the one-eyed informant, his right eye is bulging out. But after he says, "What the s**t is this?" his eye is back to normal formation.
Continuity mistake: In the scene when Cho & Dave Hatcher confront the thugs in the park, the black thug is on the right, at the back, holding a radio. He says, "Oh look, here come the policemen. I wonder what they want with us this time?" In the next shot, the radio is on the park bench, in front of his knees.