In the movie I.Robot, in the scene when Detective Spooner (Will Smith) was given 5 minutes to interagate Sunny the robot. Spooner told Sunny that he murdered Doctor Lanning, and Sunny shouted that he didnt kill Lanning and he bangs his elbows on the table which makes a deep dent on the table. Then in a minute or two the camera angle changes, now you can see under the table (the place where Sunny is sitting) and the dents from the bang disappeared.