But it is illuminating.
On this thread, CFD has not really broken any rules. She has been outright nasty, mocking, insinuating things about op, but she has not broken any rules. The rules dont say "dont bully posters", presumably because the people who made the guidelines were reasonable adults who did not think it necessary to spell it out.
Is there a fine line between being helpful and supportive, and being sarcastic and condescending? No, not really. They are poles apart, and therefore easy to spot. The first is helpful, the other makes you feel bad, and doubt yourself. And that is not what mumsnet is for. It may not break any specific rules, but it against the spirit of the forum. And that should hanging over us like a Prime Directive.
Looking at how CFD has posted on this thread, it reminds me very much of the mentality of the "cool girls in high school" and how they got away with bullying other students. They did not swear, they did not call names, it was all in how they phrased it, and how they presented, or misrepresented the op.
CFD has not broken rules outright, she has broken the Prime Directive.
While I like and respect AF, and have no clue who CFD is, this is not really in support of AF per se.
It is the principle. It could be between CitronellaCandleStorm and MacundoRainfal (and nobody would have noticed)l. It could be anybody. It is still wrong.
But, the fact that AF got suspended, and the outcry, it has made people stop and think about the issue, and trolling, and dis-ingenuity in general, and that is a good thing.