The tribunal chairman, Mr Justice Moriarty, said he had to determine the truth from the conflicting evidence given before him during the past two days.
There were a number of possible views the tribunal could take, he said.
The first was that the Central Bank, in completing an urgent and important inspection of Guinness & Mahon, "may have been unduly hasty in disparaging matters" raised by Mr Terence Donovan. Subsequently these matters have been revealed to be important.
The second view, which Mr Justice Moriarty said he did not want to phrase "like a cheap parody of a John Grisham novel", could be that the Central Bank had been "arguably indolent in policing aspects of the back-to-back loans". And he said there remained "some degree of orchestrated conspiracy" to silence Mr Donovan, who was getting "too close to embarrassing events".
Mr Justice Moriarty suggested that Mr Donovan was not inviting the tribunal to come to the latter view. Mr Donovan agreed.
Mr Donovan said giving evidence to the tribunal had been very difficult. Working relationships were very good in the Bank, he told his counsel, Mr John Gordon SC. His evidence was not intended as criticism of his colleagues; he was only reporting his recollections, he said.
Meanwhile, a senior Central Bank official said it would have been better for its investigators to have known its concerns about Guinness & Mahon.
Mr Adrian Byrne, head of banking supervision at the Bank, agreed with Mr Jerry Healy SC, for the tribunal, that it would have been better if investigators in 1988 had known about the history of the Central Bank's concerns with Guinness & Mahon.
He said he could understand that in 1988 the junior trainee, Mr Donovan, had questions about the back-to-back loans he discovered in Guinness & Mahon. He would have been surprised if a trainee had not been sensitive to these loans.
The Bank did not feel it was worth going through the history of the back-to-back loans, Mr Byrne said. "Mr Donovan's job was to ascertain that those loans were recoverable," he said. To do this Mr Donovan would have had to make sure the security on the loans was satisfactory.
The tribunal has been adjourned until further notice.