When is a CRB check not a CRB check?

Very puzzling story in the news about a child not being able to attend a council-run Christmas party because she has health problems which mean her mother has to be with her at all times, and she (the mother) would not be allowed to attend as she has not been CRB checked by the council.  That would just be another "stupid CRB check" story, and Lord knows we have had enough of them, but what makes this one even more unbelievable is that the mother HAS been CRB checked, but by the County Council rather than the parish council who are running the party. Furthermore, she has been checked at the enhanced level - the highest one there is. So what the parish council think they're playing at I don't know.  Is it the case that, like the animals in George Orwell's fable, some CRB checks are more equal than others?