This is a very interesting concept... avoiding mistakes by design, or mistake-proofing called the Poka Yoke principle. The principle is widely used in the industry and in many real life situations. Well known examples including connectors you can't insert the wrong way because they are asymetrical, or the gas nozzle example. Type of gas (leaded/unleaded for instance in Europe) corresponds to a different diameter making impossible to insert the leaded gas nozzle in a car with a catalyzator.
A more detailed definition can be found in wikipedia : Poka Yoke Article
I recently discovered an interesting example of Poka Yoke or similar: when you buy medication in Europe, you'll get pills enclosed in plastic with an aluminium cover that can much too easily be opened.
This is happening all the time, when you take a few pills with you for traveling for instance. The thing gets open, you lose the pill, a serious loss sometimes. If you buy similar pills in the US or in Canada, many times you will benefit from a different design.
Step one - the package
Step two - peeling off the first layer
Step three - getting the pill
The aluminium foil is protected by a plastic/paper kind of surface, making it impossible to open or scratch the packaging by mistake. You need to peel off the first layer and then you can get the pill out of the package. This is a very intelligent mistake-proof design and probably a reasonably cheap one.
For other well known examples of poka yoke, there is a very interesting site:
Poka Yoke Examples