His claim of knowledge is a fair point, but was he not trying to impress another sex criminal with boasts? And he's clearly got a screw loose, otherwise he wouldn't be doing any of this stuff to begin with, right? His known criminal history means he fits the crime, but then if one looked hard enough, probably quite a few others of his ilk fit it too.
Again as with the Lamplugh case, there is (for me) a crucial missing piece of exactly what happened that nobody seems able to fill in. With Lamplugh, there is a supposed sighting of her leaving a house she had shown to Mr. Ki(dna)pper. Yet the police immediately forensicated the house and have never, ever confirmed they found any sign of her - fingerprints etc - inside it. If they had, it would uphold the sighting and their hypothesis. But not a dicky bird. So was she ever there? Does the complete silence not show she never was?
With CB, the equivalent screaming question is what explains the parents' initial claims the bedroom window was open when the photos show it was not. Exactly how is MM supposed to have been taken from that room? I have my own speculations about what could have happened, but until someone states exactly what took place, and it jives with everything we know from elsewhere, then to me CB's claims sound like attention seeking.