Even non-violent self defence techniques haven't worked in my DS1's case, he still has ended up being the one in the wrong. And my DS2 would neither hit back, or be able to defend himself, due to his SN's. So he IS an 'easy target'.
I have had no choice but to complain to my school's Governors, so serious are the lack of safeguarding issues, and their culture of victim blaming, not recording incidents of bullying, not getting appropriate medical treatment for seriously injured DC's, lying on RIDDOR forms, attitude of the teaching staff and the SMT at the school.
And the combination of issues are so severe at this school that if the complaints are not effectively dealt with by the Governors, I WILL now be sending my complaint higher - to the LEA and the DfE (has to be both due to the process of Academy conversion not being finished.)
I will also, if the reaction to my complaint to the Governors be unsatisfactory, be complaining to Ofsted too. The Safeguarding issues I feel will be taken more seriously be Ofsted, and would IMO be the only thing that would make the HT change the working practices of the school, if their Ofsted 'Outstanding' rating was threatened.
Believe me, I am not going down this route lightly, it has taken 8 years and the systematical bullying of all 3 of my school age DC's, leaving physical and emotional scars on all 3, to get to this point.
But given the nature of the most recent incident, and the school's response, I am left with no choice but to continue this to the full extent, as my only remaining option is HE. Which I may yet have to end up doing, to safeguard my DC's from being used as a punchbag for others with little to nothing being done about it.