Spoilers for Isaac Asimov's Robots of Dawn.
For those who haven't ever read it, there is a highly advanced robot who became locked in an infinite loop and became completely useless because of it. There was one other robot like it, both of which were made by this one scientist guy and extremely valuable.
Sorry, read it two years ago and I'm too lazy to look up the names.
Anyway, they were trying to find out who could have possibly done this to the robot, since it required a paradox so huge the advanced robot couldn't work through it. The scientist claimed he was the only one who was capable of doing it, but swore it wasn't him.
The book is all about the detective interviewing suspects, trying to figure out whodunnit. Halfway through reading the book an idea popped into my head that seemed to be the only explanation. If it wasn't the scientist, the other other person, or..."person" it could have been was the other robot, which turned out to be right.
Yaaaay.
Usually though, with books and movies, I suck at figuring out what's really going on, when everyone else thought it was obvious.