Continuity mistake: At the beginning of the movie, Tom Stillwell is shouting instructions at the class. He calls for a stop with his hands behind his back, and the class turns and stands by as he looks...with his hands on his hips. In the reverse shot his arms are down. (00:01:50)
Revealing mistake: At the beginning, when Ivan and the two New York businessmen approach the school, the three are seen through a window from inside the school. If you pay close attention to the reflection of the students in the window, you can see that they are in no way doing anything related to what is being heard inside the school. After the class is dismissed and starts to leave, we see Ivan and the two businessmen begin to enter the school, and if you look in the window, the class is still going hard. (00:03:00)
Other mistake: As the trio of bad guys enter the dojo to challenge Jason's dad, they go past a few students, who apparently prefer getting out in the street in their karate gi and bare feet rather than take a minute to at least put their shoes on - we even see one with sneakers and belt in hand, makes you wonder if he's just gonna drop his pants in downtown L.A. That one is not the door for the locker rooms. (00:03:30)
Character mistake: In the opening scene with the mobsters threatening and then beating up Mr. Stillwell, the American flag in his dojo is hanged backwards, with the blue Union on the right. (00:04:20)
Continuity mistake: Sensei Tom Stillwell realises the threat from the bad guys being all evil in his dojo and jumps back yelling "This will solve nothin'." Before it cuts to a new view, he is looking away from the guy in a suit and looking at the others, but in the next shot he's still looking at the guy and only then checks Van Damme and the bearded dude out. (00:04:40)
Continuity mistake: Van Damme sprints when his buddy is forced to kneel before Stillwell; the problem with the cool sequence when he springboards off his back is that Stillwell in the shot when Goatee Guy went down had already regained his balance, while in this new action shot his leg is still raised. (00:05:30)
Other mistake: In the shot with the Stillwaters' car pulling in front of their new home in Seattle, on top of the luggage rack you can spot a little red item that falls off as the car stops. Coincidence or not, a minute later Jason opens the U-haul cart and grabs a box with a red cup on top. Same object or not, surely they did not travel from LA to Seattle with something precariously on top of a bag. (00:08:40 - 00:09:30)
Character mistake: Jason's dad comes out of the car and uses consistently for the first part of the movie his crutch supporting the side where he has the cast. Walking on just one crutch, you have to support the uninjured side. (00:08:55)
Continuity mistake: Jason grabs from the cart a Canada Dry box with a basketball and some blue plastic stuff on top, and brings it to the garage. He then goes back to the cart, and meets his future best buddy R.J. Madison as he...grabs from the cart a box with a basketball and some blue plastic stuff on top. (00:09:35 - 00:10:30)
Continuity mistake: Jason wants to see the garage right away, knowing he's gonna set up some cool stuff there. He brings his basketball in front of the garage door. Between that shot and the one where he opens it, the natural light has completely changed; the house is not casting a large shadow behind him, the tree is, and his own shadow moved to the opposite side. (00:09:50)
Continuity mistake: Setting up the garage, Jason picks from his box a punching ball. Notice the sticks on the right side of the box. And how when he Tarzans into the shelves a moment later the sticks have changed position. (00:10:00)
Continuity mistake: Just when Jason gets to Seattle and is playing with the punch bag, 3 wood pieces fall to the floor, then Jason sets one in it's place but in the next shot the one in the middle is back in place by itself. (00:10:20)
Continuity mistake: Jason drops the basketball he was carrying. There's a mat on the door of the trailer; when Jason picks up the ball the new kid bounced back to him, the mat is folded differently. (00:10:35)
Continuity mistake: When RJ stops his boombox in front of Jason, the fact that the two shots were filmed in separate moments is obvious; they are now at greater distance and RJ does not cast his shadow on Bruce Lee anymore. (00:10:55)
Continuity mistake: When Rafer Jason Madison III asks Jason if they just moved in, eliciting a humorous response, he has two hands on the same (left) handle, switching to both hands at the cut. (00:11:10)
Continuity mistake: RJ offers to show Jason what he can do instead of wooden dummy sparring. Jason looks at him busting moves as he leans against the dummy with both arms, but in the first shot he had only the right arm in position. (00:12:30)
Continuity mistake: RJ in the garage is doing his thing 'rapping' and doing whatever passed for music in the 80s. Part of the scene must have been left on the editing room floor, because after the close-up on his legs doing the moonwalking-y act he is about 1 meters away from the previous spot, under a different light, mounts on a box that had books on that corner (they are pushed back now), and even falls down on a bamboo mat that was not there before. (00:12:50)
Continuity mistake: When RJ falls off the shelves that Jason hastily put back in place earlier, the kid is climbing on different set of shelves; he approaches those closest to the window, but falls from some that are in the middle of the case. (00:13:00)
Continuity mistake: The protagonist is all hyped-up because of his planned cemeterial trip. He begins training in his garage; when he kicks both the punching bag and the speedball, or at least attempts to, the mats on the floor change position between shots. (00:15:00)
Continuity mistake: The obese comic relief is mocking his dad's speech as he puts him to work washing windows. At the first cut when he approaches the window you can tell time (and takes) passed, because the wet area on the wall under the window changed size considerably. The wall even basically all dries up the moment Scott spots RJ. (00:16:05)
