I made a comment to a coworker recently. Someone who reports to me has been recently given a verbal warning about their work. I requested that the coworker forward any issues about that person directly to me for the time being. I stated that she is having some work issues and it would be better not to pass errors on to her directly as she is under pressure to clear up past problems.
The coworker took this information and told my boss while at an event together that I had said my report had a chance to be fired! The boss asked me why I said that and told me to keep these things under wraps in the future. I politely stated that the coworker must have misconstrued what I said, as I would never state that someone had the likelihood of being fired, and I don't even know that myself at this point.
What is the best way to handle "he said, she said" in the workplace and prevent a false reputation?