Judging by the Prime Minister's tone, one might be forgiven for thinking that the debacle of Liam Fox, Adam Werritty and the blurred lines between official and personal relationships had been laid conclusively to rest. Far from it.

It is true that the Defence Secretary is no longer in his job, as David Cameron stressed repeatedly yesterday. It is also true that the inquiry by the Cabinet Secretary clarifies important issues, such as whether Mr Fox broke the ministerial code (he did), whether he endangered national security (he did not), and whether he made any financial gains from Mr Werritty's confused role (again, he did not).

But that is only the beginning. Gus O'Donnell's report is no whitewash, but it was limited to the specifics of the ministerial code of conduct rather than the full range of Mr Werritty's activities. Equally, although wider assessments of the balance of power between ministers and civil servants are worth pursuing, as are inquiries into the lobbying industry, it is not yet time to graduate entirely from the particular to the general. Not when there are still such glaringly unanswered questions.

Most strikingly, while Mr Fox may have made no financial gain from his involvement with Mr Werritty, is the same true in reverse? Equally, did any of Mr Werritty's sponsors, donors or clients reap any benefits from his closeness to the Defence Secretary? Without a complete breakdown of Mr Werritty's defence-related activities – who he met with, and on what basis – it is impossible to gauge what exactly he may have achieved. Similarly, there is still no complete list of the donors to Pargav, which funded Mr Werritty's extensive travels. Neither is it certain whether Jon Moulton, the venture capitalist, was the only person approached by Mr Fox for funding for Pargav; nor what the donors to Pargav believed their money was for.

Until such questions are convincingly answered, the Prime Minister cannot justifiably characterise any continued interest in the matter as a dilatory failure to keep up with events. Mr Fox may be gone from the Ministry of Defence. But the investigation of his relationship with Mr Werritty must be far from over.