The most likely explanation that they just don't want the risk associated with it in terms of the parents having a mission to ruin the teacher's life or the press desperate to keep the frothers angry taking a very intrusive dive into the teacher's life for daring to be anything other than a weak wokist as you so put it because it complicates their agenda.
That's the most likely explanation in your mind given this?
"Mr Butler said there was no formal complaint from either of the boys or their parents about the incident. "