He has worked for the commission for 36 years, has seen more than his fair share of restructures and reorganisations and is sanguine about the future. "The commission will reform, modernise and go forward in a way appropriate to it, and the new chief executive will clearly have her own ideas about that process," he says.
One thing he can be sure of is that the finances of the commission as a whole will continue to be squeezed, although he says the team of 20 that he oversees - all but four of whom are lawyers - are yet to feel the pinch. "My view is that we are adequately funded at the moment, but if the amount of legal work increases, the legal division - like other parts of the organisation - will come under heavy pressure," he says.
Dibble joined the commission after a short career in banking, followed by a law degree as a mature student and a short time at the bar. His current job began, in effect, in 2006, when new legislation created the charity tribunal, through which people could challenge commission decisions, the new list of 13 charitable purposes and the requirement for all charities to show public benefit.
Early judgments by the tribunal led to the commission taking a certain amount of flak, and Dibble admits that it "has put people under quite a bit of pressure". But he says: "It is only right and proper that if you exercise certain powers, compliance powers in particular, you need to able to justify what you've done. I think that, for the whole commission, the idea of the charity tribunal is beneficial and it has increased our accountability."
He thinks the tribunal was at first more formal, legalistic and expensive than was intended, but feels this has changed. "We, like the tribunal, want to make sure that the tribunal is accessible - and, if we're dealing with litigants in person, we will very rarely instruct counsel. We'll do it in-house, ourselves."
One of the biggest tests for the commission in recent times concerned the redefined charitable purposes: this was the decision at the start of this year to grant charitable status to the Preston Down Trust, a Devon congregation of the secretive and controversial Plymouth Brethren Christian Church. "Issues of public benefit requirement for religious charities have always been a difficult area of charity law," Dibble says.
The commission initially turned down the trust's application, and consequently was criticised by MPs and others for appearing to be somehow anti-Christian or a secularising force. "This is simply not the case," he says. "We deal with religious charities sympathetically, but they do have to comply with charity law."
The issue was eventually settled without a tribunal hearing, and some argued that this meant the law was still not particularly clear. Dibble agrees, in part. "I think the tribunal would have provided greater clarity, but what the Charity Commission has done is to provide a quite authoritative statement of public benefit requirements," he says.
Under the microscope
Dibble expects this won't be the last time the new requirements come under the microscope. "Some areas, such as the advancement of culture or community development, remain untested, so that's work in progress," he says. "I think it was always intended by parliament that the clarification of the Charities Act 2006 would be incremental, a matter to be tested in due course in the tribunal or in appeals."
That evolution is likely to involve more work, more controversy and more scrutiny of the commission. Dibble shows no signs of having been frustrated or hurt by the frequent barbs aimed at the commission recently from parliament and elsewhere. Nor does he show any outward sign of pride in his assertion, made after his trip to the International Charity Regulators conference in Australia in April, that the commission is "looked at as bit of a gold standard in terms of charity regulation internationally".
Having spent so many years at the commission, many of them as head of the legal team, how much longer does he think he will be in the role? "No idea - perhaps it depends on the new chief executive," he says. If it were up to him alone, however, he would be around for a while yet.
"The legal work of the commission has become more interesting in the past few years; it's an exciting time in many ways," he says. "We want to improve and show we are an organisation that adds value to society."
2010: Chief legal adviser and head of legal services, Charity Commission
2003: Director of legal services, Charity Commission
1978: Joins Charity Commission