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.
Continuity mistake: The bonsai tree from the cliff changes size and its amount of leaves during the film.
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.
Chosen answer: First he could have just been out of practice, but the point they made in the movie was that his moves were old, so they knew how to counter the things he did in the past to win.
pross79