Other mistake: When Miyagi throws Mike into the light switches, the lights go out but the switches never change position.
Continuity mistake: At the end of the final match, the announcement is made it's the first time in history the defending champion kept his title. Yet in Karate Kid 1 Johnny Lawrence had already won the championship twice and was there for his 3rd time.
Factual error: The storyline in Karate Kid 3, based on the happenings and reference points of the first two movies, is supposed to take place roughly about late 1984, or early 1985. However, if you look close at the beginning of the film when Terry Silver drops off John Kreese at the airport, there are several cars that are definitely later 80's models.
Continuity mistake: The bonsai tree from the cliff changes size and its amount of leaves during the film.
Continuity mistake: Towards the end, when Miyagi comes to save Daniel (yet again) he is fighting John Kreese. At one point you see the pocket protector fall out of Miyagi's shirt pocket. He never bends over to pick it up, but 2 seconds later, it is back in his shirt pocket.
Continuity mistake: When Daniel goes to get some pots from the store, the girl who is making a pot is wearing a ring on her right finger, yet in all other shots of her right hand the ring has gone. (00:29:45)
Continuity mistake: At the beginning, when John Creese and Terry Silver pull up in front of the bus, there is a red car at the side of the bus, but when John and Terry pull closer to the curb the red car has vanished. (00:08:05)
Continuity mistake: When Mike Barnes walks into Mr Miyagi's back garden where Daniel is training, they fight and Terry Silver appears. When Terry puts his book to Mike's face, in the first shot it's on the right side of Mike's face, but next shot on his left, then back on his left. (01:03:25)
Continuity mistake: When Daniel asks Miyagi to teach him how to sweep, he brings out a broom instead. When Daniel is in his car, Miyagi has the broom in his left hand and is lowering it, but in the next shot the broom is in front of him and he is holding it with both hands. (01:06:10)
Plot hole: Daniel first needs Miyagi's signature (which Miyagi refuses) to enter the tournament. However the rest of the movie focuses on Daniel's signature needed to enter instead. Didn't Miyagi officially need to sign? How did it suddenly switch?
Suggested correction: Daniel's entrance into the tournament was engineered by Silver. Mike got Daniel to sign, then had Silver or Kreese sign as the sensei. Silver started training Daniel shortly after, so he is the most likely one to have gotten him in. When the plot was exposed, Miyagi and Daniel probably contacted the tournament officials and corrected it. They wouldn't have told them about the plot since they knew it would have meant more trouble with Silver, Kreese and Barnes, so it's plausible that Daniel could have gotten into the tournament without Miyagi's signature.
Continuity mistake: When Daniel is punching the picture of Barnes, he splatters blood all over the place. In the next shot, there are only a few drops on the picture.
Continuity mistake: When Daniel is being beaten up by Mike Barnes in the Bonsai store, just after Daniel breaks the glass in the window, look to the left of the screen. There are 4 crates, 1 on top of each other, then when Mike throws Daniel away after punching him, look in the background there are 3 crates and then two next to the 3 crates piled up instead of 4, like we saw in the previous shot. (00:46:30)
Continuity mistake: When Daniel and Jessica are about to climb back up the cliff face, while Mike and the other guy are helping the sun is changing in every shot.
Continuity mistake: After Mike hits Daniel at the bonsai store he gets a bruise on his left cheekbone. The next day it's gone then it reappears when he starts training with Silverman.
Continuity mistake: When Jessica and Daniel get to the cliff to get the bonsai tree, the sun looks like 6 or 7 pm but when they are about to descend the sun is at a different position.
Continuity mistake: When Mike and the others are getting away from Daniel and Miyagi in the red car, after they avoid the train the car moves to the right twice.
Continuity mistake: As Mike falls after hitting the light switches in the dojo, a quick shot of his foot shows he is wearing black shoes when he was barefoot in all the other shots.
Continuity mistake: When Kreese is taken down in the dojo fight, he is thrown to the right and lying parallel to the mat. In a mirror reflection as Terry fights Miyagi, Kreese is seen knocked out and facing the door.
Continuity mistake: When Daniel and Jessica are about to climb back up the cliff face, they both tie the ropes to their harnesses with a knot at the end of the rope, yet when you see a shot from the top of the cliff face, you can see quite a lot of rope trailing behind Jessica which shouldn't be there.