Renewable Heat Incentive Inquiry examining botched energy scheme
Former DETI finance boss Trevor Cooper returns to inquiry hotseat
Inquiry set up after public concern over scheme's huge projected overspend
Retired Court of Appeal judge Sir Patrick Coghlin chairing inquiry at Stormont
Public hearings entering critical phase with high-profile witnesses giving evidence
We've been rifling through a lot of civil service emails, meetings and off-the-record conversations today.
No rabbits pulled out of hats but this inquiry has a habit of revealing something fascinating just when you least expect it.
Trevor Cooper's back in the witness chair tomorrow - we'll bring you coverage from 09:45.
Have a great evening!
Jayne McCormack
BBC News NI politics reporter
There was a "total lack of communication" between two divisions of the Stormont department that was running the RHI scheme, the inquiry heard.
Chair Sir Patrick Coghlin made the comment during evidence from senior DETI finance official Trevor Cooper.
Image source, PacemakerThe inquiry heard evidence suggesting there was insufficient sharing of information between the enterprise department's energy branch, which drew up the scheme, and the finance branch.
Sir Patrick described it as "such dysfunction" and Mr Cooper said he couldn't disagree with that.
There was a "flurry of activity" in DETI regarding the RHI scheme during June 2015, says inquiry counsel Joseph Aiken.
DETI official Shane Murphy says in his witness statement that "the lapse in [spending] approval did not appear to exercise energy division".
Trevor Cooper says he raised the matter of overcompensation of scheme participants at a meeting in June, and the question of whether the RHI was complying with European Union state aid rules was also raised.
He thinks the issue of the "perverse incentive", whereby people could make money by the wasteful burning of fuel, didn't emerge until the autumn.
DETI's energy boss John Mills complained that in spite of "repeated requests" his team had not received clarity about the maximum budget for the RHI scheme from the department's finance officials.
He made the remarks at the end of May 2015 in a document that would ultimately go to the department's permanent secretary as an assessment of how the department was operating.
But the criticism was subsequently removed - Mr Mills told the inquiry that he did that "at the behest" of the finance team and he was persuaded that there was a "less pejorative way of writing it".
Image source, RHI InquiryBack then, inquiry panellist and vastly experienced former civil servant Dame Una O'Brien said the purpose of the document was not to say "that everything is all right".
Asked about why a "legitimate criticism" was removed, finance official Trevor Cooper admits: "It looks bad - I totally accept that."
Sir Patrick Coghlin tells him that the removal of the criticism "camouflaged" the situation and gave "no suggestion that something's gone wrong".
DETI's energy boss John Mills had a "fixation" about getting more money for the RHI scheme instead of looking at how to sort out the problems that had led it to blow its budget, says Trevor Cooper.
There was a "bit of a spat", as barrister Joseph Aiken puts it, between Mr Mills and Mr Cooper at a meeting of the department's senior management at the end of May 2015.
Image source, RHI InquiryMr Cooper admits to having a sense of frustration at how the energy team's attitude about wanting more money while he was insisting the scheme was already over budget and there was a need to get it under control.
But he says there were no personal difficulties between him and Mr Mills that affected their work on the initiative.
He did, however, get "pretty frustrated" in September 2015 when there was a delay in bringing forward the legislation for cost controls for the scheme.
One of the officials who was running the RHI scheme made a speculative request to see whether the Department of Energy and Climate Change (DECC) could give any spare money to DETI.
DECC was the UK government department that was running the GB RHI.
Seamus Hughes wanted to know if some of its unspent budget could be used to plug the funding gap that DETI was facing.
That's met with a raised eyebrow or two from the inquiry panellists.
Sir Patrick Coghlin asks if Mr Hughes "had any reason to believe that DECC would give [DETI] spare money" and dame Una O'Brien says it "seems very strange to be doing this".
Inquiry barrister Joseph Aiken says it perhaps points to a "sense of desperation".
Inquiry panellist member Dr Keith MacLean (below) has serious questions.
He asks if the delay in alerting top DETI bosses about the RHI scheme's budget problems was due to the department's finance officials feeling "embarrassed, or ashamed" given that they'd "sat on this for two months".
Trevor Cooper says he can "absolutely guarantee that's not the case".
Image source, RHI InquiryMr Cooper says he did escalate it to DETI senior finance director Eugene Rooney, claiming he did so verbally.
He says he doesn't believe Mr Rooney expressed any surprise when he found out about the problems.
But Sir Patrick Coghlin has trouble with that - he suggests Mr Rooney "would've expressed at least some mild interest" if he'd been told that scheme had overshot its budget.
There was a "total lack of communication" between the two parts of DETI that were dealing with the RHI scheme, says Sir Patrick Coghlin.
There doesn't appear to have been the necessary sharing of information between officials in the department's energy branch, which draw up the scheme, and the finance branch.
Image source, RHI InquiryThe inquiry chair describes it as "such dysfunction" and says the panel has "major difficulties" in understanding" how the department worked.
He tells Trevor Cooper that finance branch officials don't seem to have looked at the scheme's regulations to get an understanding of how it worked.
The witness admits that he "can't disagree".
Jayne McCormack
BBC News NI politics reporter
If you were following the inquiry at the start of this month, you'll remember the boss of the energy charity Action Renewables admitted he may have misled an investigation by the Charity Commission linked to the RHI scheme.
The inquiry chair Sir Patrick Coghlin said the "inescapable inference" from the evidence he'd seen was that Mr Doran was "misleading" the commission.
Image source, Charity CommissionThe commission had closed its original investigation into Action Renewables but as a result of the revelations at the inquiry it has reopened the case.
Its move was revealed in a letter (above) to the Alliance Party MLA Stewart Dickson, who complained in the wake of Mr Doran's evidence to the inquiry.
Mr Dickson says: "I hope this will be taken extremely seriously and any wrongdoing or irregularities are appropriately addressed."
Sandra Thompson sent another email to DETI's finance branch on 30 April 2015 warning that based on the latest budgeting forecasts the RHI scheme would run out of money in mid-September.
Mr Cooper says he's unsure who would have received the email as it was sent to a generic address.
Image source, Getty ImagesIn any case there was no reply until 19 May, a gap of three weeks.
Mr Cooper agrees that the email should have been escalated to the top DETI civil servant, permanent secretary Andrew McCormick.
We're up and running again.
Inquiry junior counsel Joseph Aiken takes us back to spring 2015.
In March, Sandra Thompson of DETI's energy division sent an email to finance division regarding concerns about the RHI scheme.
Image source, RHI InquiryFinance official Jeff Partridge told the inquiry he was "under considerable pressure at work at the time", had leave booked for the Easter period and was reassured that the budget for RHI had been secured.
Nothing was done until Mr Partridge's boss drew his attention to the email in early May.
Mr Aiken asks the witness whether this was acceptable.
"No, absolutely not, and ultimately I'm responsible for the finance," Mr Cooper says.
Image source, Getty ImagesIt's been a highly technical witness session so far with not a little frustration expressed by the panel.
Time to get some fuel on board in preparation for the afternoon.
We're moving on to the spring of 2015.
Officials at DETI's energy division noticed a distinct increase in RHI uptake.
Energy division official Stuart Wightman asked a number of questions of DETI's finance division seeking urgent clarification on a possible budget problem.
Image source, Getty ImagesMr Cooper confirms that Mr Wightman was identifying a significant issue that needed to be addressed.
"What you're being told is 'increasing numbers - budget problem'," says Mr Aiken.
There is a dramatic pause before Sir Patrick calls the break for lunch.
Back from a short break, Mr Aiken introduces a series of civil service emails dating back to June 2014.
The inquiry counsel says that from these exchanges it seems that "discussions are being had over the question of funding".
Image source, Getty ImagesThere is some confusion over how the scheme was being funded from AME (Annually Managed Expenditure) from HM Treasury).
AME is generally used for demand-led programmes, such as welfare and pensions.
Mr Cooper argues that it would have been better if "there was a separate [AME] classification for RHI".
"Like an unstandard AME? Or an unusual AME?" offers Mr Aiken.
This non-standard form of expenditure is something we've been hearing about in witness sessions from way back before Christmas.
The lack of understanding meant that many officials were under the mistaken impression that Treasury funding for the scheme would be uncapped.
The session is thrown into confusion when it tries to work out what was being said about the budget for the scheme during a meeting of officials on RHI.
Sir Patrick tries to tease out the threads, but comes to the conclusion that there is "total confusion" in the unreliable notes from the meeting.
Inquiry lawyer Joseph Aiken apologises when he says, "I can't help but smile".
Image source, Getty Images"It shouldn't be a source of amusement. It's public money," says the chair.
There's a distinct air of frustration hanging over the inquiry as everyone troops out for the morning tea break.
Panel member Dame Una O'Brien is surprised that, since they had no policy background, Mr Cooper and Mr Thomson didn't go and discuss the DECC document with their colleagues in the DETI energy section.
"You've got officials who are steeped in the detail and you're not talking to them. It doesn't really make a lot of sense," she says.
Image source, RHI InquiryThe witness agrees.
Dame Una asks if there was a culture of not engaging with junior staff, and Mr Cooper replies that there was a very open culture in the department.
Mr Cooper says he was certain that the RHI scheme was going to be "monitored very closely" and that there would be "the ability to amend tariffs" in the year after it opened.
"We were going to closely update and review tariffs," he said.
"We had a value for money and a cessation mechanism.
Image source, Getty ImagesSir Patrick asks Mr Cooper why he believed this to be the case. He also asks why Mr Cooper did not seek out people with knowledge on the regulation surrounding the RHI scheme to understand how it could be stopped.
Mr Cooper says he did not think to ask someone with a regulatory background about closing the scheme, and that he takes Sir Patrick's point.
Mr Aiken moves on to an exchange between Mr Cooper and David Thomson, who was one of three top managers DETI.
Mr Cooper says the exchange took place before the summer in 2014.
He recollects that Mr Thomson called in to ask Mr Cooper's advice about a DECC (Department of Energy and Climate Change) business case on degression.
DECC ran the parallel RHI scheme operating in GB
Image source, RHI InquiryDegression is a mechanism that allowed the tariff to be lowered in response to increased demand.
The lack of such a mechanism was one of the factors that allowed the Northern Ireland scheme to spiral out of control during the spike in applications in autumn 2015.
At the time, Mr Cooper says that DETI was operating the RHI scheme on the basis that there was no degression.
He says he was told by a DETI official that it was already possible to stop the scheme in-year.
Inquiry chair Sir Patrick Coghlin is bemused to say the least at the arrangements for DFP approvals.
He notes Mr Cooper's comments that there were conditions attached to every approval but no time to ensure that these were carried out.
Image source, RHI Inquiry"That just sounds like complete organisational disaster," Sir Patrick says.
"How on earth did you ever get to work efficiently?" he adds.
Mr Cooper chaired the committee meeting that resulted in approval for the RHI scheme being granted by the Department of Finance (DFP) in 2012.
However, DFP limited its approval until 31 March, 2015.
Image source, RHI InquiryThis was how far ahead HM Treasury funding for the scheme had been secured.
Mr Cooper was not given the email from DFP granting the approval with its 2015 limitation.
The required date for re-granting financial approval in 2015 was missed, contributing to the crisis that overcame the scheme.