If you hear people talking about others that you may know, good or bad, the best action that you should take is to just Let it be!
If you say anything within the conversation then you have opened yourself up to being involved and excused of any wrong that might come of it. Just Let it be!
I make the above comment because it has happened to me and others that I know as well. We were trying to set the truth, but the conversation became distorted and then we were accused of saying something wrong or bad. We learned to for now on to just Let it be! Good luck to all I hope it never happens to you.