DUP could learn from humility and transparency of Andrew McCormick
In the calm, measured tone that has marked his Civil Service career, Dr Andrew McCormick delivered his evidence to the Public Accounts Committee yesterday.
There were no rhetorical flourishes or gimmicks. But it was his business-like, understated style that made his words so explosive.
Dr McCormick said he believed that Arlene Foster's former special adviser (spad) Andrew Crawford had successfully exerted influence to keep the Renewable Heat Incentive (RHI) scheme running at the higher rate of payment. Mr Crawford denies the allegation.
Initially, Dr McCormick referred to unidentified individuals in the DUP. However, when pressed, he named Mr Crawford. He did so a little bit - but not very - reluctantly.
A meeting he had with former DUP Enterprise Minister Jonathan Bell to review ministerial papers in December may have been recorded "without my knowledge or consent", Dr McCormick said.
Perhaps his lack of reticence to the committee yesterday was made in the knowledge that he has been recorded making the same assertions privately to Mr Bell, and that this tape will be put in the public domain.
Dr McCormick's claims have clout because he is so highly thought of across the political spectrum at Stormont. "An absolute gentleman, the best permanent secretary at Stormont, and straight as a die," is typical of the attitude towards him.
His evidence also carries weight because he didn't try to deflect blame from his own. On several occasions he threw up his hands and said he had no excuses to offer - the flaws in RHI should have been spotted far earlier by civil servants.
The DUP could have learned a lot from his transparency, and had Mrs Foster adopted his humble, no-excuses stance, she wouldn't now be potentially facing political ruin.
Dr McCormick's second major revelation - that he had received emails suggesting that insider information had been given to firms to allow them to "get in quick" before the RHI scheme was altered - was equally earth-shattering.
The DUP had no heavy-hitters on the PAC. Its MLAs who were present delivered an underwhelming performance and appeared pathetic as they read what seemed to be pre-prepared questions.
In contrast, at the social development committee's Red Sky proceedings in 2014, Sammy Wilson and Gregory Campbell fought their party's corner robustly.
Trevor Clarke said little at yesterday's meeting, and Alex Easton might be fine on discussing parking tickets in Bangor, but he looked totally out of his depth yesterday.
The likes of Christopher Stalford or Jim Wells - the latter watched from the public gallery - would surely have been far more effective through both experience and force of personality.
The PAC hearing was yet another disastrous day for the DUP. Mr Crawford was Mrs Foster's spad in the Department of Finance at the time.
Alliance's Trevor Lunn quizzed Dr McCormick on the issue of ministerial responsibility, and the answer was unequivocal. Whether a spad's actions were authorised or unathorised, the buck stops with the minister.
The DUP's steadfast opposition to a public inquiry - until relatively recently - can be viewed as even more unreasonable now, as can Mrs Foster's refusal to temporarily stand aside to allow for a preliminary report by independent investigators. This would be standard practice in any other normal democracy. The party's complaints of witch-hunts and media bias have been increasingly exposed as threadbare.
The DUP didn't have a strong hand coming into the 'cash for ash' scandal, but it couldn't have played its weak cards more appallingly.
On almost every matter that has arisen, it seems that the truth has been dragged out of it, kicking and screaming.
A prime example being party spad John Robinson declaring on Monday that his family home farm didn't benefit from RHI, only for it to emerge on Tuesday that his father-in-law was a beneficiary.
We already know that Mr Crawford's brother, along with former spad Stephen Brimstone and his brother, were beneficiaries of the RHI scheme.
Although there is no insinuation that any of the individuals did anything wrong, the revelations naturally cause concern with the public.
The greatest indictment of the whole sorry saga was summed up by UUP MLA Alan Chambers. All those who made disastrous decisions on RHI remain in place. Bizarrely, the only person suspended is Jonathan Bell.