Continuity mistake: When Milton pushes the vole down the ramp and hits the wall it falls off the board. In the next shot it's back on the board.
Other mistake: They say that when Jack is back, they will be in college, but they were in Year 8 and all 14, so they would be, at most, in Year 12.
Continuity mistake: The rebels are in their stocking feet when they narrowly escape the Zompyres at the lab, but they are wearing shoes when they get back to the base.
Suggested correction: They had removed their shoes prior to entering the lab, remember the scientist said 'thank you' to them for it plus the Zompyers were distracted by the dancing so the rebels could have grabbed their shoes before exiting the building.
True for most of them, but Jack kicked his off in the lab and in the opposite direction of where they fled, so he should have been shoeless when they got back to their base.
Other mistake: They act as if Carson was part of the dojo with the whole crew, but Kim was a Black Dragon when the show started.
Revealing mistake: Kim is supposed to be hanging from the tree by the ropes around her wrists, but you can see she is standing on a platform.
Continuity mistake: The Bobby Wasabi dojo receives the amazing Punch Master Elite that is apparently not even available in stores yet, however you can see the piece of equipment in a previous episode, S2E15: A Slip Down Memory Lane. The Punch Master Elite can be spotted in the back left corner of the dojo in the first scene. Other than that you can just barely see it if you look closely into the dojo when the camera goes to that angle in the scene where Jack regains his memory and breaks the under 15 record for brick breaking. Aside from these 2 sightings, you don't see it again because it is a flashback episode, and beyond that, you actually don't see it again until S2E20 when Milton opens it as a gift from the Mayor, awarded for tremendous bravery in capturing an escaped convict.
Kickin' It on Our Own - S2-E21
Revealing mistake: At the karate demo, the Black Dragon student never breaks the second board, the kid holding it drops it as the kick comes close.