An enemy at the gates of Downing Street? An investigation, as I know only too well, would have bought time, given everyone the space to breathe and allowed hitherto unknown facts to emerge before final conclusions were reached. By closing this down early, No 10 and the Met have created a problem that was avoidable. Downing Street is bristling with digital CCTV cameras that would highlight who was where and for how long when Mitchell tried to leave on his bicycle by the main entrance. The video footage would provide incontrovertible evidence, enabling any investigator to know exactly who he or she should interview. It might even identify other, perhaps independent, witnesses. Although they have no audio capability, the cameras must have captured the encounter between Mitchell and the officers, and this, along with eye witness accounts, would help to establish whose version of events is to be believed. We need to know. A minister has more than suggested that he has been well and truly "verballed"" up by the police. This is a very serious allegation. If there is material that would assist in ascertaining what happened, then it should be investigated and the results, including all police records (with their proper context), put in the public domain. The incident has also exposed particular challenges for Boris Johnson, the Tory leadership contender, and Boris Johnson, London Mayor responsible (through the office of the Deputy Mayor for Policing) for the oversight of the Met. Johnson, now a second-term Mayor and undoubted political hero of the Olympics, has had No 10 and the PM fairly rattled over the past weeks and months. This incident, though, required him to respond with his Met hat on. It provided the opportunity properly to support the force, and in particular the officers concerned who have had their truthfulness challenged by Mitchell. However, to do so would have meant aiming another broadside at the PM, something that Johnson might have thought was pushing (even) his luck. So he took his time and there was very little from him until midweek, when he mentioned in passing that Mitchell was lucky not to have been arrested. One can't help wondering how Johnson's now elevated status as a real challenger for the Tory leadership is going to enable him over the next few years to concentrate on one of his principle elected functions, namely holding the Met and commissioner to account. The Tory leadership and the woes of the PM ought to be a sideshow for Johnson, but this incident suggested that the two may not mix well together. Indeed, sometimes they may be in conflict. Which takes me on to what this incident might have exposed about the future oversight and accountability of the Met and the police service in general, following the November elections for Police & Crime Commissioners (PCCs). Rewind several months to before the demise of the Metropolitan Police Authority and consider what would have happened if Gategate had occurred then. As was the practice, the full authority would have met last Thursday. On live television, with the national and local media present, the commissioner would have had to explain all the circumstances of the incident to a committee whose membership was drawn from all the major political parties (and some independents). He would then be questioned in detail about his decision-making. I have no doubt that high on the agenda would be the decision not to investigate the matter further. No commissioner I have known enjoyed these moments. They could turn - and often did - into a political point-scoring circus but, crucially, it was all on-the-record and very public. The commissioner and his senior staff were frequently given a rough ride, sometimes rightly so. The fact that you knew that you would have to account for your actions most certainly informed your decision-making. Who really challenges the commissioner now and who will challenge other chiefs in the future? Where is the transparency and the public accountability around key decisions? No doubt all these questions will be answered as the PCC model beds in across the country over the coming months. However, as a pointer, one of the first acts of the new Deputy Mayor of Policing was to instruct the commissioner not to attend a public scrutiny session of the Greater London Assembly. Elections for PCCs, public service cuts, Winsor recommendations and Leveson all promise to make it a long winter ahead for the law and order community. Gategate, though, tells us a lot about modern politics and policing. It is, in the words of Malcolm Tucker from The Thick of It, an "omnishambles." The only way to resolve it is to turn back the clock and for there to be a proper investigation. John Yates is the former UK Head of Counter Terrorism