YES.
The previous answers did not address the question as asked, namely:
If I disclose the reason behind termination, everybody agrees with me that it was right, but this behavior in particular wasn't in front of other ones eyes, so they didn't notice it.
What I'm most afraid is that they may think that termination had some other reasons, jumping to conclusion: "He got fired because of that totally rational behavior, so managers are crazy and they may fire me too for some other stupid reason". It's clear without saying how this damages the moral.
I know it's disrespectful to talk behind back of other people, hence the dilemma.
You are a businessman in charge of a team. All that matters to you, professionally speaking, is the team. Team morale is important, and that morale is shattered, absolutely shattered, when one of their numbers suddenly disappears. The worst motives are suspected. You have to say something.
Just do it the right way. Stick to the facts, avoid adjectives, don't exaggerate, briefly explain your opinion, and leave it at that. Don't go into details, don't belittle the former employees. There is nothing belittling about the truth, and it's impossible to be successfully sued for slander if it is true.
