Two very important lessons we learn today:
1. People talk, even if they are rabbis and there are far and in between people who are modest and private who you can trust to tell them something and they won’t spread it.
2. It is illogical to say that if a person did something wrong in his youth even if very severe he still has that problem now, after so many years even if you did not see him repent. If he seems to be acting in a kosher way there is no reason to suspect him of his previous deeds.
Bottom line: People grow up (most of the time)! Therefore there is no excuse to speak lashon hara about them.