Am I a bad parent?:(

My son is 5 and going through the process of diagnosis, he’s got a great school who do one to one support and meditation/ nurture sessions. 

There was an incident whilst he was at a family members home where an older relative, primary school age nearing secondary and also autistic had asked my son to pull his trousers down and photograph his genitals. He’d then asked my son to photograph him. This happened allegedly when their grandmother had left the children unattended for around 10 minutes. 

I spoke to the older boys father about this and spoke to the headteacher at my sons school. Not in a derogatory way about any children involved, purely as the older children had been studying sex Ed I thought this might have made it a primary focus in this child’s mind and he was exploring it in an inappropriate way. I was also worried about the risk of images ending up on social media and in the wrong hands.

since this my family have completely ostracised my son, they have told their children to ignore him and have been ‘telling tales on him’ constantly to try and get him into trouble. They’re insulting me to him and have even contacted social services etc to make false allegations. All this is breaking his heart and sending him into meltdown:( is this my fault? I feel if I hadn’t of done anything he wouldn’t be suffering now. I don’t know if I should move schools, which in itself would be a huge upheaval?