The former head of a Stormont department's energy team has admitted he did not read a crucial handover note detailing flaws in the Renewable Heat Incentive (RHI) before leaving his post.
John Mills took over the Department of Enterprise, Trade and Investment's (Deti) energy division in January 2014 during a key period of the flawed green energy scheme.
At the RHI inquiry yesterday, he explained how he had commissioned a document laying out the problems with the scheme, including concerns flagged up by a whistleblower, businesswoman Janette O'Hagan.
Despite this, Mr Mills said he could not remember seeing the document and said he believed department officials would have briefed his successor about any concerns.
Mr Mills denied he lacked interest in the scheme, saying he had an extremely demanding job that required him to keep multiple plates spinning.
The panel, chaired by retired judge Sir Patrick Coghlin, heard a decision within Deti meant that the introduction of the domestic RHI scheme was deemed more important than sorting out cost controls for the non-domestic scheme.
Mr Mills said that while the decision was made before he took up the post, he had "failed to correct" it.
He said stretched resources meant Deti officials were working in an "extremely onerous" environment and struggled to be across all the details of every scheme in their responsibility.
Most teams, he said, dealt with four or five issues, but his team had 12.
"I can deal with complex issues as a generalist and I can deal with several, but 12 not so much," Mr Mills said.
While the scheme closed to applicants in 2016, 30 people are working on it today.
Mr Mills said that for most of his tenure, there were only two - one full-time and the other part-time.
Mr Mills said he often raised the issue of resources, but limited finances led to a reduced number of posts.
The cutbacks, he said, "didn't give me much confidence that extra resources would be forthcoming".
Before leaving his role, Mr Mills commissioned a handover note outlining the immediate actions his successor had to take to address key flaws.
He said he could not remember reading it, and at the time RHI was not deemed as high-risk as other projects.
One issue detailed in the note was a method of cost controls called tiering that was marked "as a matter of urgency".
Mr Mills said new staff should have escalated that point to him after reading the handover note.
During yesterday's evidence, Mr Mills was also quizzed about why the concerns of whistleblower Janette O'Hagan went unheeded.
"Successive people didn't pick up on Mrs O'Hagan, including in my time," he said. "It's hard to say why."
In his defence, he said that while Deti often received critical emails, it was unheard of for them to contain such important information.