In his second day of testimony at the Cameron inquiry into faulty hormone receptor tests at Eastern Health, former clinical chief Dr. Donald Cook said he believes the root of the problem lies with corporate restructuring in the 1990s.

Cook testified Thursday that he was beside himself when he discovered in 2005 that the health authority had a big problem on its hands.

"Well I was absolutely devastated. I just couldn't believe that was happening — what was going on," Cook said. "I mean it was shock and disbelief."

Cook has previously testified that he was alerted to one inaccurate test result in May 2005, and subsequently ordered a group of tests be redone to determine if it was an isolated case.

When 25 of the 33 re-tests returned with different results, Cook told his superiors at Eastern Health about the problem. They ordered more retests and submitted the labs to external reviews.

Cook said Thursday that the major restructuring Eastern Health went through in the 1990s is to blame for quality problems in the labs because during the restructuring half of the region's management positions were eliminated.

"The managers were the people who, basically, were the glue that kept the system together," Cook said.

Eastern Health is the largest integrated health organization in Newfoundland and Labrador serving a regional population of more than 290,000, and employs more than 12,000 people.

Eastern Health was formed April 1, 2005, merging seven regional health organizations. It oversees more than 80 hospitals, health-care centres, long-term care facilities and community care sites.

Cook said when the managers were laid off in the restructuring employees were left confused about who had authority over what, and there were no longer managers to ensure quality assurance programs were followed.

The public inquiry, headed by Justice Margaret Cameron, is investigating why hundreds of patients received faulty hormone receptor tests. The tests are used to determine a course of treatment for breast cancer.