This situation came to mind today, altho it happened in the past to a co-worker. She told me one day that our female boss had flattened my co-worker's tire on her vehicle. I found this hard to believe but didn't say so.
Then a couple of weeks later I heard our boss speaking on the phone to someone and she herself said that she had flattened our co-worker's tire.
What would have been appropriate things to say or do (either by my co-worker or by me)? I can't imagine how horrible it must have felt to have this done by one's boss, and yet I still find myself wondering if it was really true? And yet I heard our boss say that she had done this.