PPS 'carefully considered supergrass case
Unreliable and ravaged with alcohol and drugs.
That was how a judge last week described the two main prosecution witnesses at the end of the loyalist supergrass trial last week.
Mr Justice Gillen acquitted 12 men of all charges against them, including nine who were charged with the murder of leading UDA member Tommy English.
In his judgement, the judge demolished the credibility of Robert and Ian Stewart, two self-confessed UVF members who admitted their involvement in the murder and agreed to give evidence against their alleged accomplices.
In return, they each had their sentences reduced by 19 years and are now living at a secret address outside Northern Ireland, with assumed names.
Mr Justice Gillen said the two men had lied to the police and the court and that their evidence had been "contradicted by independent evidence on many occasions".
His comments led to widespread criticism of the decision to take the case to court and calls for an end to that kind of trial.
In his first broadcast interview since the trial, the Director of Public Prosecutions has defended the use of the Serious Organised Crime and Police Act 2005, which allows evidence from "assisting offenders" to be used in court.
Barra McGrory QC said the decision to prosecute those on trial had been taken after an extensive debriefing of Robert and Ian Stewart by experienced police officers.
They then recommended that the prosecution and PPS lawyers examined the material they provided before taking the case to court.
So why had the discrepancies in their evidence highlighted by Mr Justice Gillen not been identified by those who carried out the debriefing?
"The difference is that Mr Justice Gillen was able to come to those conclusions after extensive cross-examination by no less than nine different legal teams poring over the material," Mr McGrory told the BBC.
"That is the function of the trial court.
"The risk here is that the prosecutor might seek to circumvent the function of the trial court by conducting what is really a trial within a trial, in order to come to the decision as to whether or not to prosecute.
"That is not our function. If that was our function, this would be a totalitarian state without the benefit of an independent judiciary.
"Nevertheless, I do accept that there is a basis for being extremely careful in the weighing up of evidence in every case, and particularly in a case such as this, but I am certainly satisfied that there was a very careful consideration of the material in this case."
The PPS is conducting a review of the evidence given by the Stewart brothers to establish whether they breached the terms of the agreement that resulted in their sentences being reduced by 19 years.
If the conclusion is that they knowingly failed to provide the assistance, their reduced sentences could be reviewed.
The PPS director also defended the cost of the case, which it is estimated could be around £20m.
"In general, I have to say that I would be very concerned about a practice on behalf of the prosecution that would factor in the potential cost of a case in the decision, as to whether or not it is legally justifiable to take the case to court.
"That would set a very dangerous precedent and I don't think that would be in the public interest."
Mr McGrory denied that last week's acquittals and the criticism from the trial judge were major embarrassments for the service he leads and the police, and said they did not discredit the legislation that made the trial possible.
As a newly qualified lawyer during the 1980s, he witnessed the collapse of the original "supergrass" system, which produced 100s of convictions, the majority of which were later overturned.
The PPS director said the 2005 SOCPA legislation was entirely different because there was greater transparency about the criminal backgrounds of the offending witnesses, and what they received in return for their evidence.
"The lesson that has to be learnt from this case is that very great care has to be taken in the evaluation of evidence of this kind.
"That is not to say there is no merit in accomplice evidence, but the greater the scale, the greater the care that has to be taken."
I asked if he had any concerns that last week's judgement may have fatally undermined the 2005 legislation and jeopardise similar trials in future.
"No, I don't," he replied. "Mr Justice Gillen was very careful to say his concerns were the particular witnesses in the particular circumstances of this case, that that was not to say that the procedure wasn't a valid procedure.
"Far be it for me to say that there should never be another such case again. What I do have to say is that when there is such a case coming before the prosecution service that it will be very carefully evaluated."