That's the key. Should.
Should is not what it is in reality.
"Should" is what Cat posted. However, that is not reality. The reality is that if you post something incriminating about a co-worker/boss/workplace in a public forum, you're gonna get in trouble.
What kind of consequence was he looking to instill? Termination? Verbal warning? Suspension? As I wrote earlier, if there is something about harassment/disparaging a co-worker in a contract or policy then he could easily fire her because calling him creepy and whatever else would fit under that. He has more than enough cause to let her go (and if you guys have no contracts, in the eyes of the law he is still justified. If it is an at-will employment kind of deal, he wouldn't even have to use the "she called the VP a creep" out, he could fire her just for the fuck of it).
If it was going to be a verbal warning, I would have just done it. Now it sounds like you have escalated the situation and there is the potential that it could cost both of you your jobs (which may be fine for you, but does she have 3 options she could go to at the drop of a hat?).
If it was termination or you could tell he was leaning that way, then disregard the above and fight what you think is worth fighting for.
The young lady that works for me has been hit on by this VP, as well as a couple of her friends. She has rebuffed his advances, not interested, etc. For months he has been aware of her FB page. She and her girlfriends saw him at the gentlemen's club completely making a fool of himself, it reached the point apparently that the dancers started getting creeped out and the bouncer had to come over and tell him to relax. Now, all of a sudden, the FB is an issue because the VP basically shit all over himself.
To me, it's not the fact she's been doing this, it's the fact the VP now doesn't like what was said and he's now looking for a pound of flesh for this and being rebuffed by her and her friends. It's more than just protecting her, this guy is WAY overstepping his boundaries. He is also a bully and wants to have his way, and when he doesn't he turns on you in a heartbeat. He wants to fire her for this, but trying to be all smooth at the same time about it and wanting me to do his dirty work for him.
I know for a fact that as an employee of the Department of Education, we are bound by an official code of conduct to not refer to any member of staff, or particular students, using social media. There is a huge contention about having parents or relatives of children on there as a contact, because shit can really hit the fan. A friend of mine got investigated by the commission because he'd posted stuff about how he hated certain children in his grade that he was teaching on.
Difference between the two situations is that obviously your contract states you have to be careful of what you put out there. I know common sense should dictate that automatically that should be the case, but to me if there's nothing in writing about this then it's a non-issue.