I think it's that combination of inexperience and delay in ensuring everyone gets updated safeguarding training, across all the agencies, together with this 'egg-timer' model of reporting concerns that needs sharpening up. When all staff can confidently go straight to social services AND get feedback to inform them their concern has been acted on, things will improve. If deceiving parents can fob the authorities off, going back to the source of the concern and complaint can be illuminating because it can identify how the parents and the child behave towards different professionals, whether that be consistent lying, disclosures from the child to a trusted person, or direct observation of neglect or cruelty.
Having an artificial bottleneck through which to squeeze concerns clearly stifles communication. Data protection and confidentiality rules, whereas being able to speak direct to those who have taken the concern to a manager can shed so much more light on what is going on. Perhaps a Crimestoppers type system for reporting concerns anonymously, and a broad access system for sharing concerns, with feedback so that the reporting professional can gain and provide better quality information if social services don't or can't act. And how about empowering children to be able to say their school mates, or themselves, are in difficulties?
It's certain that the findings from the case review will say the same thing yet again. Poor communication, system failure, training needs not met, too much time doing paperwork and so on. There'll be a blitz on training and auditing, leaving no cover for active cases whilst those staff are away from their jobs, a drop in recruitment, promotion into managers jobs taking what skill there is away from the frontline, and then yet another high profile case to disgust us all.