Following the Soham murders, police forces were instructed to retain information for longer (and indefinitely in many cases), and to consider carefully whether such information should be included in enhanced DBS checks (while erring on the side of caution).
Ian Huntley's behaviour in the area he'd previously lived in had resulted in him coming to the attention of the police but nothing was actually proven against him. Consequently (because the system didn't exercise the same degree of caution as is now used and, indeed, because all written records of his suspicious behaviour had been destroyed) he wasn't flagged up as causing any concerns when education officials checked on whether he had a criminal record or not.
So there are good reasons as to why the system is now more thorough than it used to be. However it can sometimes seem to appear somewhat too strict . . .
About a decade ago we had a post here on AB from a teacher who, when seeking to change jobs, had found that there was a reference on his enhanced criminal record check to allegations being made against him which suggested that he'd tried to groom a pupil for sex. That was despite the fact that neither the police nor his employers had ever taken the allegation seriously enough to question him about it. He was totally unaware that anyone had ever made such an allegation and (without even knowing the name of the child that he was alleged to have tried to groom) totally powerless to disprove it.
At the time of that AB post there was no appeals procedure in place so, unless he was able to persuade the police to remove the reference voluntarily, he was stuck with it for life.
Since then an appeals process has been introduced, allowing people who're subject to enhanced DBS checks to challenge what appears on them. I assume that the guy in the BBC new article had already exhausted that route before taking the matter to court.
I suspect that many teachers (and others who might come into contact with young people) have adverse information recorded on police files, which might well surface when they apply for an enhanced DBS check. Canary42 asks if Cliff Richard is likely to have such a note on file. The answer to that is probably 'Yes' (although, in practice, it's probably unlikely that he'll never need a DBS check anyway). Indeed, I suspect that there may have been such a note on file for many years anyway. Whenever he visited the school I taught at in the 1980's (which happened on several occasions), the staff were always advised to ensure that he was never left alone with teenage boys.