You're engaged in a facebook conflict with a friend who writes a nasty comment about you and signs off before you can reply. what conflict approach is your friend using?

I believe the answer is: Snipping

In conflict approach, snipping refers to the act of hostility and run away before the target f hostility is making a response.
This approach is considered as the effort to avoid achieving resolution in the conflict, while having the full intention in hurting the target.