when I helped out for 2 years at school with reading as a volunteer parent, I went in completely "neutral", I had no suspicions or paranoia, nothing.
But I saw that 1 child with severe SN who had, supposedly, 1-1 for 25 hours a week, never got any 1-2-1 as he was calm and undemanding. The lady who was supposed to work with him was asked to manage 2 disruptive children, often by taking them out of the classroom to go and sit with them in the corridor. One of them used to beat and kick her, he had serious problems but no statement.
She told me she only got to spend 5 hrs a week with the child she was supposed to spend 25 hours with.
As I know she was not supposed to tell me (it was a weak moment and she was in tears) I never told anyone, not even the mum of the boy with SN.
I am still not sure if that was the right thing to do.
But I was shocked and it opened my eyes. This was a good teacher with an average class, who did the best she could, but something in the system stinks if this is how it goes.