RowanMumsnet, you were excellent.
Even the bare bones of the issue tells a story, without spin or side. The fact that this is a rare occurrence, that the poster in question refused to have their post deleted and freely offered their details, That you didn't consider it defamatory, and yet the complainant went to the trouble of getting a court order, and your wonderful air of authority making it all seem a little tedious and unnecessary. Especially in light of the reason for anonymity being the real life issues of abusive relationships and domestic violence.
The facts speak for themselves. As always.