The former chief medical consultant of the Blood Transfusion Service Board did not check which viral inactivation technique was used by a company supplying the board with blood products in the late 1980s, the tribunal heard.
Dr Vincent Barry said he did not know that the form of viral inactivation used by the Armour pharmaceutical company was insufficient to inactivate the hepatitis C virus and had been blamed for the infection of four haemophiliacs in the State.
He said he inquired with colleagues in Britain about the best way of heat-treating blood products and learnt the most effective treatment was heating the product at 80 for 72 hours.
Mr John Finlay SC, for the tribunal, put it to him that this was not the form of heat-treatment agreed by the BTSB with Armour when it entered an arrangement with the company in 1987.
"I didn't know that. I wasn't really brought into that at all," he said.
He said he was not asked for his views on fractionation (the process which describes the manufacture of clotting factors) as he had no experience of blood products.
Mr Finlay said even if fractionation was not his speciality, it might have been expected that he would satisfy himself that the correct method of viral inactivation was used as he was the board's chief medical consultant.
Mr Finlay asked Dr Barry if he had inquired about the form of viral inactivation used by Armour, when the deal with it was sealed.
"I can't say I did, no. I didn't. They would be the experts in that regard," he said.
The tribunal was told that Dr Barry was invited to a meeting in Pelican House in June 1987 to discuss viral inactivation techniques before the BTSB would meet Armour on the possibility of fractionating blood concentrates under contract from Irish plasma, but he did not attend.
Dr Barry, who retired at the end of 1987, said he did not remember any debate in the BTSB about the Armour method of fractionation.
In December 1987 an arrangement was entered into with Armour to make factor 8 clotting agents from Irish plasma at a plant in West Germany. The company returned a by-product of the plasma called supernatant to the BTSB from which factor 9 for haemophilia B patients was made. This product infected four haemophiliacs with hepatitis C, including two children.