So if I understand the article correctly, SK denied that there was evidence of Rochdale-style grooming gangs operating in London, while having read reports of sex crimes that Maggie Oliver claims indicate the existence of such gangs.
He hasn't denied having read the reports, just denied that they indicate what it's being claimed they indicate, right? Surely the key point is exactly what's in the reports and whether it was reasonable to support the conclusion he did.
An inquiry might be a good idea, but I don't see anything yet, without much more information, to incriminate him.