The Karate Kid Returns - S6-E14
Revealing mistake: When the box falls on the kid's head, Randy and Mark run out of the store. When they run out, the mall stores in the background wave or move revealing that it's not an actual mall set but just a backdrop.
Answer: In seasons 1 and 2, each Binford tool had a unique model number, but from season 3 onward, they were all numbered 6100 as a running gag.
Cubs Fan ★