really ? garbage can ? thats about the stupidest answer i have ever heard 
In fact in one of the cases I had personally witnessed a socket was found in a garbage... It can happen much easier than you may think of.
Once a tool was found in an aircraft itself in a location that you should be blind or totally distracted to live it there - but it happens for real and it is frightening when you understand how and what could happen if no tool monitoring was properly performed.
I been turning wrenches for over 25 years and have never in my life thrown a tool in the garbage can other then one that was broken.
Have you been working in aviation maintenance? The fact that you personally have never thrown a tool to a garbage can it does not mean that it never
accidentally happened to you and you just were unaware of it. If you don't monitor tools you will not discover it.
Actually once I had found a pliers under my cars hood (luckily it hadn't damaged anything in the engine) and several times I had found inside the car other tools.