Lawyers for gardaí and the State have accepted that a warning by a judge to a key witness in Ian Bailey's civil action was a "harmless error" and it would have been preferable if it had not happened in front of the jury.
However, Senior Counsel Paul O'Higgins told the Court of Appeal there was ample evidence before the jury about the credibility of witness Marie Farrell and the jury would not have been prejudiced or influenced by the warning.
Mr O'HIggins was making submissions on the second day of Mr Bailey's appeal against the jury's decision to reject his claim of a garda conspiracy to link him to the murder of Sophie Toscan du Plantier.
He has submitted 17 grounds of appeal, many of which relate to rulings by the trial judge John Hedigan during the five-month long case.
Yesterday his lawyers said key Ms Farrell was unfairly disparaged by the trial judge who gave her a warning in front of the jury about perjury.
Responding today, Mr O'Higgins agreed with the appeal court judges that the warning could be characterised as a "harmless error".
He also said it would have been preferable if the warning had not been given in front of the jury.
He said the recording of Ms Farrell's interview with GSOC, in which she said she could not tell the difference between fact and fiction, was "the most telling evidence about her credibility, more so than anything else".
He said the judge had also told the jury they alone were to determine her credibility.
Mr Bailey sued An Garda Síochána and the State for damages.
He claimed he was wrongly arrested on suspicion of the murder of Ms Toscan du Plantier at her holiday home in Schull in West Cork in 1996, and he claimed some gardaí had conspired to frame him for the killing.
On day 62 of the action the trial judge, John Hedigan, struck out many of Mr Bailey's claims, ruling that they were not made within the time limit required by law.
A claim that certain gardaí were involved in a conspiracy against him in relation to Ms Farrell, was allowed to go to the jury.
But the jurors found against Mr Bailey after almost two hours of deliberation.
Mr Bailey was ordered to pay the multi-million euro legal costs associated with the case.
A stay has been put on the costs order pending the outcome of this appeal.
Mr Bailey has always denied being involved in the murder of Ms Toscan du Plantier, whose body was found near her home on 23 December 1996.
The French authorities have issued another European Arrest Warrant in an attempt to have Mr Bailey extradited to stand trial for voluntary homicide.
An application to have that warrant endorsed will be heard by the High Court on Thursday.
Mr Bailey is expected to challenge the attempt to extradite him.
Lawyers for Mr Bailey also say Mr Justice Hedigan should not have dismissed most of Mr Bailey's claims towards the end of the case after more than 60 days of a hearing.
The judge withdrew the bulk of the case from the jury after the State argued it had not been lodged within the legal time limit.
Senior counsel Paul O’Higgins said it had been "absolutely clear" from the beginning that the State would be arguing the claims were made out of time.
Mr O’Higgins said Mr Bailey's lawyers had mentioned this in their opening address to the jury but he accepted it was "never mentioned again" until the State wrote to Mr Bailey's lawyers on day 61 of the case to inform them they would be making the argument.
Ms Justice Mary Finlay Geoghegan said where such a defence is to be raised there could be a question as to whether to permit a claim to proceed before a jury and evidence to be called.
"Not only is there a huge element of cost and time wasting, there is probability that if part of the claim is then statute barred you are inevitably prejudicing the ability of the jury to decide clearly on the basis of evidence only relevant to the issue to which the statute does not apply."
Mr O’Higgins said it was "an unusual case" which went "very heavily to various people's reputations and involving as it did allegations which were brought forth in the course of the plaintiff's case".
However Mr Justice Hogan said he understood the position of certain witnesses who might wish to give evidence in the face of serious allegations to vindicate their reputation.
However he asked if there was "not an inconsistency between saying I want to go into evidence to clear my name and then towards the end say 'by the way the bulk of this claim is statute barred'?"
Mr O’Higgins said he would not agree there was an inconsistency in this approach.
He said the extent of the personal, professional and public damage capable of being done to gardaí against whom extraordinary allegations were made was "quite huge if they were seen to duck examination on such matters or failed to put forward denials".
Mr Justice Hogan said: "Supposing the entire case had been ruled statute barred, one has to ask quite apart from the question of cost what was the whole point of the exercise? Could that not have been determined on day one or two that it was statute barred?"
