I don't suppose for a moment the man thought his daughter would announce the settlement on Facebook and she was only joking about getting a European holiday out of the proceeds. Seems very harsh of the school to counter sue the man which has probably caused them even more 'negative' publicity.
I had to sign a confidentiality agreement relating to a settlement from a company last year. I was told by my solicitor that if I breached the confidentiality agreement the company would be entitled to reclaim the money... Sometimes when you sue and win it isn't because the company has openly admitted liability, particularly when it hasn't gone to court, as in my case, and I suspect in this case too. It's done so that the company who settled can maintain their reputation and not draw others to sue them in similar circumstances.