The high profile trial, which lasted four weeks, nearly collapsed on two occasions.
The first instance was on the very first day of the trial, when Mr Justice Barry White was forced to discharge a juror.
This came about after a member of the jury panel who was not selected rang the jury office to say that he had struck up a conversation during jury selection with one a woman who was selected for jury service.
He gave evidence that she expressed the view that Mr O'Reilly was 'guilty anyway.' This man identified the woman juror and she confirmed she had been speaking to him but claimed the view she expressed was not her own, but rather a rumour that she'd heard in work.
The second time the trial nearly collapsed was three days later when a portion of the book of evidence "made its way into the jury room." The jury brought its presence to the attention of the registrar, enquiring whether it was intending for them. When counsel agreed to proceed with the case on the proviso that the jury promised they had not read any portion of it.
Once called back in, the Judge asked them whether they had done so and they collectively shook their heads.
The trial continued for the second time.
The Judge also urged the jury on two separate occasions to ignore media reports of the trial; once at the beginning of the trial and again, towards the end, when prosecuting counsel Mr Denis Vaughan Buckley SC brought it to the attention of the Judge that jury members had to pass by a large amount of spectators who were queuing outside the court each morning, waiting to see the day's proceedings.
This call came after defence counsel Mr Patrick Gageby SC brought the media coverage of the evidence of Mr O'Reilly's lover, Ms Nikki Pelley, to the attention of the court.
The Judge agreed with Mr Gageby and said: "It certainly seemed to me that some newspapers were carrying what could be called 'lurid headlines'." He therefore repeated his suggestion that they ignore media reports of the murder.