I found an interesting article over at linuxjournal.com which I think is a topic that every supervisor, manager or CEO should be familiar with. The topic of how much power your admins have, and what happens when one of them leaves the company. The article give some very good advice that everyone should be familiar with, from what tools to have on hand, to a few software suggestions in case you ever have to get into a system that an admin has kept under only his control.
Over the years, I have worked for several different companies, both large and small. I have seen many co-workers come and go over the years, and luckily I have never been tasked with having to deal with a disgruntled admin that left on poor terms.
Check out the article, and familiarize your self with some of the tools, that you may possibly be tasked to work with some day. This is a topic that most of us think, "This will never happen where I work", but you can never be sure. Familiarizing yourself with this information now, can save you quite a bit of time if you ever have to perform any of these tasks. There are also some very good suggestions as having multiple admins knowing the root passwords, to doing background checks on your employees when they are hired. You will have to analyze your environment and see what works in your work place, as every company is different.