The contradictions between the evidence of Mr Dermot Ahern and Mr Joseph Murphy jnr are almost too numerous to take in, but a quick tot during yesterday morning's evidence revealed at least 13 points on which the two men differ.
Mr Ahern cannot agree on the amount of the payment to Mr Ray Burke that was discussed during their meeting in mid-1997, nor on Mr Murphy's professed knowledge about the sale of his company lands.
They disagree on what the developer Mr Michael Bailey told Mr Murphy, whether Mr Murphy had checked "all the records" of his company for evidence of a payment, and on many other matters.
What is astonishing about this level of conflict is that the two meetings between the men took place only 2 1/2 years ago. Mr Ahern, who was checking out the allegations then circulating about Mr Burke at the Taoiseach's behest, made detailed notes of both meetings immediately afterwards.
The number of contradictions would be even greater except that the tribunal has skirted around many of the personal comments Mr Murphy alleges Mr Ahern made to him.
But even more astonishing from yesterday's evidence is that Mr Murphy has never asked Mr Bailey anything about the meetings in Mr Burke's house in 1989, at which Mr Bailey was present.
Mr Murphy revealed yesterday that from the time of the first article alleging a payment to a politician, in March 1996, it was clear that the "property developer" referred to was Mr Bailey.
In December 1996, the journalist Mr Frank Connolly specifically told him that Mr Bailey stood along with JMSE at the centre of the allegations being made by Mr James Gogarty, yet Mr Murphy never asked Mr Bailey if he was at the Burke meeting, or what he was doing there.
At the time of Mr Ahern's inquiries of him in June/July 1997, with the political world in convulsions and storm clouds breaking over his company, he spoke to Mr Bailey by phone, and again failed to ask him what Ms Patricia Dillon SC, for the tribunal, referred to as "the central question".
As Ms Dillon said: "I do not understand why it was so important to tell Dermot Ahern about the conversation with Michael Bailey, when the most obvious question you should have asked was what happened in Ray Burke's house in 1989."
"That's pure speculation on your part," the witness replied.
Over five days in the witnessbox, Mr Murphy has proved a confident, fluent and assertive performer. Unlike so many other witnesses, he has avoided slipups and internal contradictions during his evidence.
The Murphy case is like the mechanism of a clock, complex and tightly interlocking, but at times it seems almost too perfect, especially when considered alongside basic common sense questions the companies still find difficult to answer.
Why, for example, did Mr Murphy go straight from his second meeting with Mr Ahern to see Mr Roger Copsey, the financial controller of JMSE at the time of the payment in 1989?
"I just decided to go and see him," was the witness's not quite satisfactory answer. After all, Mr Ahern had not told him anything new during their second meeting, and Mr Copsey had been asked before if he knew of any payment to Mr Burke and said he did not.
This time around, Mr Copsey remembered "something about a political contribution" though he could not recall the date, time, amount or recipient. Either Mr Copsey is familiar with frequent political contributions or he has a bad memory. As for JMSE, the next largest contribution to the £30,000 it gave to Mr Burke is a measly £1,000 it passed on to the PDs.
So why did Mr Murphy not then go back to Mr Ahern to tell him that new information had come to light?
Mr Murphy offered two explanations yesterday; first, that he wanted to wait until he had the full information and the "jigsaw puzzle" was complete; second, that his "priorities had changed" after his wife was taken to hospital and his son fell ill.
Phone records were produced to show that Mr Murphy and Mr Ahern spoke to each other by phone three times on the morning of Mr Burke's statement to the Dail on September 10th, 1997.
Mr Murphy said the Fianna Fail minister for looking for information about political payments JMSE might have made to other political parties. "It would be a good line for Ray Burke to attack the opposition with," he quoted Mr Ahern as saying. "He said: `If Mr Burke's speech didn't work, they would have no problem putting him out to grass'," Mr Murphy added.
The phone records prove Mr Murphy's contention that he spoke to Mr Ahern on that day - Mr Ahern, in evidence, could not recollect the conversation - but, confusingly, the sequence and number of calls is different from the way set out in his memo to the tribunal.
In the afternoon, Mr Frank Callanan SC, for Mr Gogarty, made some inroads into the core of Mr Murphy's case, which goes: why would we make a payment to a politician to get planning permission on lands we had sold?
But as Mr Callanan pointed out, the Murphys had not sold the lands at the time of the payment to Mr Burke in June 1989. In fact, Mr Bailey's offer for the lands was only confirmed in November of that year.