Star Trek - Camera Dolly Trips
In the episode "The Naked Time", Scotty is using a phaser to cut a hole in the wall to regain access to engineering. Just as he finishes cutting the hole, the camera dollies in. But the dolly trips on something or someone and you can see the whole camera shake accompanied by a crashing noise. My guess is that they did not want to shoot this scene again because the wall cut out (by Scotty's phaser) would have been to time consuming to create again.