[jonnycowboy]

In both of those examples likely the blame is on the company and not the worker.

In Joe's case, any aluminium dust may stick on the broom - solution, two seperate 20$ brooms, problem solved. Nevermind aluminum and iron shaving take a significant heat source to trigger, at what part of the factory was this corner cut?

In Roy's case, it is a problem with the process, not with the worker. 1" drill bits get dulled, and are very hard to actually break. Was the jig properly set up? Was Roy involved in setting the process up and understand tolerances and bolt holes (including adding a go/nogo tool if required). These are the questions that need answering before passing the blame onto the minimum wage employee.