Brown quote on the Sir Gus bullying pep talk

The ever insightful Bagehot at the Economist has been speaking to Gordon Brown about his alleged “pep talk” from Sir Gus O’Donnell. Here’s the prime minister’s response:

“The cabinet secretary has made it clear that he’s had no inquiries, there’s been no reprimand, there’s been no private message to me…[The] story is completely wrong.”

This denial is becoming more and more comprehensive (although there is still some room for speculation). I’m just a little confused over why it took the cabinet secretary so long to make it clear.