Is the truth always a good thing?

Most who look at the title of this post would probably answer this question with a resounding yes. And in most cases I would agree. I am sure most of us out there have several exceptions though, I know that I have a few select exceptions. And usually it involves the possibility of someone either getting physically hurt or killed. Here is a scenario to think about though.

Say you worked with a person who at first seemed normal and very nice. Throughout the time you worked together though you noticed some peculiar things about this person. One day you see this person outside of work unexpectedly and they tell you they are looking for another job because the current one isn't paying enough. The next day, when you know this person isn't going to be at work, you tell your boss what was said just to give them a heads up. Shortly there this person is fired from the company for reasons unknown to those besides HR and your boss. Later you find out some of the reasons they were fired. And from what you understand this person is like bat shit crazy.

A while later, you see this person out in public again and they come up to talk. The first thing you think is "oh shit. please don't let them come over here to talk to me cause they are bat shit crazy". They come up to you and talk and ask you what you have heard about why they were fired.

The question here is this. Would you tell the person the truth about what you have been told, or would you lie and tell them that you haven't heard anything? Why would you do one of these? Is one better than the other? Is a lie better than the truth in this situation?

Ask yourselves these questions and post your answer below as I am curious to see what other people would do.