escaped
Let's put this into context ......
It's a weapon that the parent can use against the school.
The school cannot publically explain the situation.
And most importantly, the school will NOT disclose any information about the child.
That is what posters on here meant by no one having the full story, or knowing the background.
The very fact that the school have publicly apologised and said their staff will be trained further in policy shows they believe they were in the wrong so no explanation is needed. I am quite sure that if there were legitimate reasons for their stance, they would have said that they couldn't comment on individual cases but stood by their decision. You don't always need the full story to know a mistake has been made.