An employee makes a simple mistake. He's overly concerned that he'll lose his job because he's a contractor, and he doesn't see the opportunity to prevent others from making the same mistake as a result. Given how many organizations are relying on contractors for staff augmentation, what can they do to encourage mistake proofing over fear?
How other employees and managers react to mistakes plays a large part in how someone will react when they make one. If others place blame, then it is only natural to be fearful of the consequences. But if they look at the system to see what caused the mistake to occur, they encourage contractors to do the same and learn. It is by making mistakes and failing that people learn to adapt, be more attentive, and become better problem solvers.
So the next time someone makes a mistake, ask questions. Question everything. Find out the root cause of the mistake and see if there's an opportunity to prevent it. But use it as a learning opportunity, not a witch hunt.