Revealing mistake: Towards the end of episode 2.18, "Bye, Bye Birdie", Tim drops to the ground in the back yard while trying to avoid the helicopter. When Tim gets up, you can see the grass (carpet) move and wrinkle up.
Revealing mistake: When Tim is falling, crawling and rolling on the snow-covered ground in the final scene, none of the snow clings to him or his clothing. He does not even get damp, even when he is lying on his back in the same spot for several seconds.
Continuity mistake: After Tim smashes Al's display cabinet, it cuts to Tim, then back to the workbench and the wrecked cabinet. The pieces of china and the pieces of wood on the bench differ in the two shots. In the first shot, there are two whole teacups, one whole plate and a bit of a shelf on the bench (the shelf is on the right side of the screen), in the second shot we see a broken tea cup, one broken and one whole plate, and the piece of shelf has disappeared.
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 ★