A Stormont department committed a "manifest error" in the tendering competition for multi-million pound deals to resurface Northern Ireland's roads, a High Court judge has ruled.
Mr Justice Horner also identified a lack of transparency in a process where one firm was awarded more contracts than it had the resources to carry out.
In a critical assessment, he found no satisfactory explanation for the lack of any minutes from a meeting about the procurement exercise.
The verdict came in a legal action by civil engineering company Northstone (NI) Ltd.
Northstone is suing the former Department for Regional Development (DRD) over its handling of a tendering competition for public road resurfacing.
Proceedings centre on eight contracts awarded in 2015 to carry out work across Northern Ireland, with a total estimated annual value of up to £52million.
The object of the exercise was to find the most economically advantageous tender for each contract, based on a criteria where price was weighted at 70% and quality 30%.
Instructions provided for bidding firms set out how successful operators were expected to have enough skilled and available resources to work at more than one location.
Multiple tender submissions also had to include separate and complete packages for each contract.
A marking system was used to evaluate the quality of bids. Operators able to demonstrate excellent equipment and resources would score five out of five.
Northstone was ranked first in one of the eight contracts it tendered for, coming second or third in all the rest.
Another firm who bid for seven contacts obtained top ranking in six.
The court heard that company was awarded five out of five responses despite identical submissions and duplicating personnel and plant for each competition.
This apparently meant it could provide site engineers for four contracts at most.
A meeting involving departmental officials to discuss multiple awards was held in September 1015, but no minutes were provided.
Mr Justice Horner said he had difficulty understanding why no record of any discussion about the issue of duplication in the six contracts was available.
"This is a telling omission," he said.
"If minutes had been taken and lost I would have expected to be told this in no uncertain terms.
"The other alternative explanations are that there are minutes but that as these undermine DRD's defence they have not been disclosed.
"Alternatively, the decision to keep no minutes was a deliberate one because DRD was fearful of creating a hostage to fortune.
"Neither of these explanations reflect well on DRD."
The court was told the Department - and the Northern Ireland Civil Service in Northern Ireland - had no policy for when meetings should be recorded.
If correct, the judge stressed, plans need to be drawn up.
"The DRD should be accountable to the tax payer and its decision should be transparent and lawful," he said.
"The records of its meetings, especially where they relate to the award of contracts worth millions of pounds, should be accurately minuted as a matter of course.
"In this instance I was offered no explanation other than it was informal meeting. I do not accept that this an adequate or acceptable explanation."
Ultimately, the firm which achieved top-ranking for six of the contracts withdrew from two of them.
According to the judge it never intended to be successful in all tenders, and was probably as surprised as the Department at the outcome of the competitions.
That company's actions "spared the DRD its blushes", allowing the resurfacing awards to be announced.
Northstone is seeking damages if it can prove the Department acted unlawfully in the awards to other contractors.
But at this stage Mr Justice Horner was only dealing with any flaws in the marking process, and an alleged breach of equal treatment in resolving concerns about a capacity to perform multiple contracts.
He ruled that the Department should have been alert to the rival firm's inability to perform more than four contracts.
Competition rules were found to be "opaque, imprecise, equivocal and lacking in detail".
A company won six out out of the seven contracts bid for with identical tenders, the judge pointed out, but only had the resources for four.
"There was a manifest error made by the DRD in giving... a mark of excellence in two answers in three contracts," the judge held.
The department then permitted it to withdraw from two of them before the awards were made.
"The treatment of the unsuccessful runners-up was unequal and discriminatory," he added.
With the firm able to select which contracts it would carry out, Mr Justice Horner said the treatment of unsuccessful runners-up had been discriminatory.
He concluded: "There was a lack of transparency, unequal treatment and breach of the principle of non-discrimination."