Getting fired is never pleasant, and it’s even worse when it comes as a complete surprise. Getting fired as a surprise while you’re driving your car must be really awful. That’s how Yahoo! Inc. reportedly fired its CEO Carol Bartz on Tuesday.  

Rarely is the way someone leaves an employer reported in such detail, so Bartz’ parting is a lesson for anyone doing due diligence. People leave jobs every day, but the way they leave (Fired? Quit? Amicable? Contentious?) is every bit as important to know if you are thinking about doing business with them.

What are you supposed to do when someone hands you a resume that reports four jobs worked in the past 15 years? You certainly want to verify that they really did those jobs, but then the hard work begins. You should want to find out why they left each job. Unless they’re as famous as Carol Bartz, you have to call people who were there at the time.

You won’t find any commercial database that will tell you something like: “He was roundly hated by the Board but negotiating his package took months because he had some dirt on two of the board members and they felt they couldn’t move too fast.”

The Bartz episode has something else to say about due diligence: what kind of directors can’t even wait a day to summon their CEO to a meeting to get rid of her? Depending on your point of view, they were endlessly patient with a bad executive until they snapped, or unusually cold-blooded in the way they dealt with their most important employee.

If you needed a new director and were considering one of Yahoo’s board, you would want to know how Bartz was treated to help you make up your mind.