I'll just say it...
Yes he went extreme on the situation, but he was in a very emotional state. I'm sure her outcome will be not as harsh, but at least ingrained in her mind that she shouldn't disrespect her parents openly on facebook.
The problem is that this is what leads to stupid overreactions in the first place. It's what led to her overreaction and his overreaction. And in North Carolina, it leads to many worse overreactions.
The wise person has some presence of mind about these things.