The tribunal chairman, Mr Justice Flood, said the "adversarial factor" present in the tribunal had been introduced by counsel for the Murphy group, Mr Garrett Cooney SC, and Mr Colm Allen SC, for Bovale Developments.
He was giving his ruling rejecting submissions from Mr Cooney, who was not present, that his clients had been accused of "wrongdoing" by the tribunal.
He said the legal team for Bovale and the Murphy group had used "virulent language" including calling Mr James Gogarty "a malicious and artful liar."
Mr Justice Flood also rejected Mr Cooney's claim that Mr James Gogarty's legal team had been "acting in an auxiliary role to the tribunal team."
Mr Justice Flood said: "Mr Cooney's assumptions for each one of his complaints is based on a fundamental fallacy - namely his clients are being accused of wrongdoing by the tribunal.
"That is not so. The tribunal repeats that it is concerned with a factual inquiry as to how certain events came to take place and factually why they took a particular form or sequence.
"There can be no doubt what were the instructions of Mr Cooney and his colleagues. Mr Gogarty's credibility was put in issue from the moment the tribunal sat.
"The pursuit of this issue has operated to introduce a deeply adversarial aspect to the process. While this development was unfortunate, it is within Mr Cooney's clients' absolute right to raise and pursue it. It will be an issue which the tribunal will have to adjudicate upon," he added.
He said Mr Cooney could not complain if Mr Gogarty's legal team presented its case in an "equally virulent" fashion. He "regretted" that the issue of Mr Gogarty's credibility had taken up to 14 or 15 days of evidence.
Mr Justice Flood summed up his ruling by stating, "There is no real foundation for Mr Cooney's complaints that the legal representation for Mr Gogarty acted in an auxiliary role to the tribunal team.
"Mr Gogarty's legal representatives have simply responded to the charges against Mr Gogarty's integrity. If at any time there was any truth in Mr Cooney's complaint, then objections should have been taken to it at the time."
On the subject of wrongdoing he said, "There are no allegations made by the tribunal against Mr Cooney's clients."
He added that the tribunal simply required their account of the events "in relation to the sale of said lands and/or the connection (if any) of the payment to Mr Raphael Burke to the said sale."