A legal challenge to a Police Ombudsman's ruling of collusion in the Loughinisland killings will be reheard before a new judge.
Six Catholic men were shot dead as they watched a World Cup match in the County Down village in 1994.
Lawyers for the ombudsman and victims' families had asked him to withdraw.
They argued there was a potential public perception of bias as he had previously been involved in a similar case against the Ombudsman's office.
On Friday, Mr Justice McCloskey said the legal test for him to step aside had not been satisfied but that he would step aside anyway.
One of two retired RUC officers who mounted the legal challenge to the ombudsman's finding of collusion said he appreciated the dilemma the judge faced and said he was relaxed about the decision.
"We accept what Judge McCloskey has had to stay, we have no fears in the whole issue being re-run again," former assistant chief constable Raymond White said.
"In fact, we are delighted that our issues in relation to the way the ombudsman's office has been operating for over a decade now have been taken seriously."
Emma Rogan, whose father Adrian was one of the six men killed, said she welcomed the announcement of a fresh hearing into the case.
"As the families, we respect the judge's decision to step aside and he is going to do that.
"We are delighted that our report still stands in its entirety - the report that we got in 2016 is still the report that's on record."
She added: "All we ever wanted was the truth - that's it bottom line. Everybody deserves it, it's human decency for people to know and for people to acknowledge what happened to their loved ones."
The families' solicitor, Niall Murphy, described it as "the most unprecedented" outcome to a judicial review he had ever seen.
"What we have now is an opportunity for the police ombudsman and the families, as interested parties, to re-engage in a brand new reflection of the legal issues raised and we look forward to doing that as quickly as possible," the lawyer said.
Mr Murphy added that the new hearing would be "another stage in the process" of a case which had raised very serious issues that "give rise to public confidence in the administration of justice".
In his ruling, Mr Justice McCloskey said that the families of those killed at Loughinisland had "become engulfed in a maelstrom" of a legal system that has been "far from straightforward".
The judge said that "our legal system will not have served the families well if they are not given the opportunity of having this case heard by a differently constituted court".
The men who died were Adrian Rogan, 34, Malcolm Jenkinson, 53, Barney Green, 87, Daniel McCreanor 59, Patrick O'Hare, 35, and Eamon Byrne, 39. Five others were wounded.
Loyalist gunmen burst into the Heights Bar and opened fire on 18 June 1994 as they were watching the Republic of Ireland play Italy in the World Cup.
No-one has ever been convicted over the attack.
Two police officers challenged the legal basis of the report and Mr Justice McCloskey found in their favour in December.
In 2001, when he was a barrister, Bernard McCloskey QC, was involved in an unsuccessful challenge to a report by former Police Ombudsman Nuala O'Loan which found there had been failings by the RUC during the investigation into the 1998 Omagh bombing.
It had been previously claimed in court that Judge McCloskey, in his previous life as QC, had represented Raymond White in that legal challenge.
The judge said this was not the case.