Mistake is a mistake, even a minor one.

Every company always has few employees like to hide the mistake they make during the work. hoping the mistake won't affect their work reputation or even the personal life. Some of them pretend nothing happened, or try to destroy the evidence. and the worst one always blame somebody else frist.

they often believe if they try hard, they could get away the troubles. if they actually hid the mistakes successfully, would they be ok forever?

Well, i guess it depends on how serious the mistake will be. if it is just a minor problem, for example, wrong spelling in technical manual, maybe nobody will take it seriously because most of them would catch in revising process anyway. if it is a problem cost company millions dollars, whether you like or not, everyone would know right away.

Despite people still could have chance to get away the trouble, but for myself,  i would rather to tell employer the truth, because mistake is mistake, even a minor one, you have to live with the consequences of those mistakes you made, and most likely, it would be painful, but over the long term , you would be grateful the decision you make,  because nothing can replace a peaceful mind.