Dubious, check their tos.
In my opinion, you should've just reported & deleted the person's posts. They were expecting retaliation and you fell for it. In war you'd have lost your company to an ambush through such irascibility.
15. Disputes
You will resolve any claim, cause of action or dispute (claim) you have with us arising out of or relating to this Statement or Facebook exclusively in the U.S. District Court for the Northern District of California or a state court located in San Mateo County, and you agree to submit to the personal jurisdiction of such courts for the purpose of litigating all such claims. The laws of the State of California will govern this Statement, as well as any claim that might arise between you and us, without regard to conflict of law provisions.
If anyone brings a claim against us related to your actions, content or information on Facebook, you will indemnify and hold us harmless from and against all damages, losses, and expenses of any kind (including reasonable legal fees and costs) related to such claim. Although we provide rules for user conduct, we do not control or direct users' actions on Facebook and are not responsible for the content or information users transmit or share on Facebook. We are not responsible for any offensive, inappropriate, obscene, unlawful or otherwise objectionable content or information you may encounter on Facebook. We are not responsible for the conduct, whether online or offline, of any user of Facebook.
[...]
WE WILL NOT BE LIABLE TO YOU FOR ANY LOST PROFITS OR OTHER CONSEQUENTIAL, SPECIAL, INDIRECT, OR INCIDENTAL DAMAGES ARISING OUT OF OR IN CONNECTION WITH THIS STATEMENT OR FACEBOOK, EVEN IF WE HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
[...]
