I wasn't even slightly surprised by this and I think it happens far more than is reported.
In my experience, schools which don't want an open narrative are usually the worst imaginable.
My DD and DS were both violently bullied whilst at primary school, which was an academy run by the diocese of Oxford. I begged the school leadership to intervene but received excuse after excuse. They also failed to report to the police under prevent. They told me and my DH we were racist and I was slagged to death to volunteer PTA parents by the headmistress.
It became a witch hunt against us, meanwhile, my DD especially was coming home covered head to toe in bruises and vomiting at the idea of attending school.
They made her out to be the issue, making her see a child psychologist who told her that Mummy and Daddy are making her sad and the boys involved (of which there was 6, all twice her size) were being mean as she annoyed them. Lovely bit of victim shaming.
The final straw was DS being viciously punched to the ground at pick up time in front of me and several other shocked parents as he went past to meet DD from her classroom door. I will never forget the yelp of pain as he hit the floor. The boy involved - who I had been told was not asked to apologise as "in his culture boys and men don't say sorry" smirked. Teachers saw this and told me off for getting upset.
I was then ordered to a meeting and told because I had begged a teacher, through tears, to intervene, that this was "aggressive" and "abusive" towards staff and i would need to collect by arrangement after school. I was then told if I didn't like it I could remove my children.
In the end I did so and I informed the police regards the terror related threats spoken by the two ringleaders and how one of their fathers had attended school and intimidated myself and another parent. They took it under prevent and raided three homes at 5am. They also put three boys on CPO and they contacted school to advise they had failed to follow procedure.
We did ask for a meeting to complain but they refused, and slagged us to death to their new school at the time- they were horrified by the records and said they couldn't understand why my children were blamed.
Schools now can do as they wish, there is currently a secondary in Reading where if a parent asks for clarity on a sanction for a minor issue, they are sent a banning notice.