Since there are no documented cases of it, yes, I am speculating, as are others who have studied this topic a lot more closely than any of us have.
I disagree that it would make headlines, at least in years past. Disney's PR machine can and has quashed negative press before. Whether they would be able quash a story like that now due to the advent of social media and increased national attention paid to them (and with it, national outlets), remains to be seen. The company could also, in theory, propose a "hush money" agreement to the affected individual in exchange for indemnification.
All of this to say, it might have happened before when there was not as much national media attention paid to Disney and there wasn't social media, but if it were to happen today, I'd bet it would come out.