Well, I will probably looking at a divorce in a year's time or so, and if I was ordered to turn over my facebook password my very first action would be to delete my profile.
Then you would potentially face penalties for spoilation of evidence in which case you could potentially face imprisonment and a jury would be permitted to "assume the worst." Good job. (Note: I am NOT a lawyer and I am NOT offering legal advice)
There is very little future in being right when your boss is wrong.