The Department of Finance guidelines which determined the form of contract awarded to Magahy and Company are confusing and in need of review, the Department admitted.
Mr Jim O'Brien, assistant secretary at the Department, told the Public Accounts Committee (PAC) that the so-called "green book" on public contracts could be interpreted in different ways.
The Comptroller and Auditor General, Mr John Purcell, described the green book as "totally inadequate" for the types of services that had developed since it was drawn up in 1994. He said some categories of services were "in never-never land".
The green book differentiates between tenders for consultancy services, which must be open to applicants across the European Union, and executive services which need only be advertised in the State and so limit the number of candidates who apply, but the difference is not clearly defined.
Legal advice from McCannFitzGerald solicitors to Campus and Stadium Ireland Development (CSID) was that the management services needed to run the campus project were executive services and did not require EU advertising.
The former CSID chairman and chief executive, Mr Paddy Teahon, said the legal advice, based on the green book, was also that the executive services team should be chosen first and a fee negotiated with it afterwards.
The fee was controversially agreed as a percentage of the total cost, whatever that turned out to be, and payments were made monthly regardless of how the project progressed.
Mr Purcell said price was normally the number one criteria in awarding contracts. He had never come across an executive services contract in a public sector context before.
"We may have had legal advice to go one way but the principles underlying public procurement certainly were not followed," he said.