This is why you keep a paper trail of who you've hired and have them keep a paper trail of what they've done. You can show what you've done and what you haven't

This is why you keep a paper trail of who you've hired and have them keep a paper trail of what they've done. You can show what you've done and what you haven't! You could engineer some sort of conspiracy to keep specific misbehavior off the paper trail, but that's difficult. Increasing the difficulty of cheating is a good thing.