His resignation, more than eight years after he was appointed chief executive of the Otago board, was announced yesterday.
The move comes as the board seeks National Health Board help to solve the impasse over Queenstown health services and a team from the national body assesses the adequacy of Dunedin Hospital systems.
When the Otago Daily Times suggested people might look at those matters and ask, "Did he jump or was he pushed?", Mr Rousseau responded: "Tell me a time in the last eight years when I could have resigned when you could not have levelled that question at me."
Asked about the political pressure in his role, Mr Rousseau said anything publicly funded involved politics.
Balancing "all of these stake-holders" was "part of health - if you don't like that you shouldn't be in the game". It was also not a place for someone who wanted to be popular, he said.
The complexity of health decision-making was such that if there was more than 50% agreement on a decision involving change, it was probably not a good decision, Mr Rousseau said.
"It means perhaps you haven't pushed the envelope far enough in terms of what needed to happen".
When he came into the Otago job he advised the board he would give it seven years, but it would have been "completely inappropriate" to leave at the beginning of last year when the merger of the Otago and Southland district health boards was not completed.
Mr Rousseau, who began his working life in South Africa as a pharmacist before becoming an executive in the pharmaceutical industry and then moving to public health in New Zealand, said he would be looking for something different.
He did not have a job lined up, but indicated it was likely he would have to move away from Dunedin and possibly even go overseas for what he described as the last third of his career.
Health Minister Tony Ryall, approached for comment, thanked Mr Rousseau in an email response, saying he had "one of the hardest jobs in DHB-land", and he was looking forward to continuing working with him.
Acting board chairman Paul Menzies, who was the previous Southland board chairman, said Mr Rousseau would have been a stalwart for the region for nine years by the time he left, and "that longevity speaks for itself".
The merger of the two boards, which had been "pretty much accepted" by the communities, was a great achievement and "more than anyone else in New Zealand has managed to do".
Finding a replacement would not be easy.
Asked to select something of which he was particularly proud, Mr Rousseau chose both the merger of the two boards, and the redevelopment of Dunstan Hospital.
Former Otago chairman Richard Thomson praised Mr Rousseau for his role in the Dunstan Hospital development, saying he had the courage to come to the board and say he thought it had made the wrong decision over the initial plans.
Mr Thomson said he was sorry Mr Rousseau was going because he had done "a bloody good job" in an extremely difficult position, and was possibly the longest-serving DHB chief executive in New Zealand.
He had been prepared to fight in Otago and Southern's corner, something which had not always made him "friends in high places".
The battle to retain neurosurgery in Dunedin was a good example of that.
The executive director of the Association of Salaried Medical Specialists, Ian Powell, who has often publicly criticised Mr Rousseau's leadership style, said yesterday he wished Mr Rousseau well and had no other comment to make.
Former Otago board chairman and inaugural Southern chairman Errol Millar said it would be some time before people realised the huge loss of Mr Rousseau's departure.
He was enormously hard-working and positive, with the courage of his convictions, and would be a hard act to follow.
In the last six months of his time with the board, he wanted to see the future of Queenstown health services "sorted", and be able to have a "good handover" to the next chief executive to ensure the new leader was well prepared, Mr Rousseau said.
Brian Rousseau
• Age: 52.
• Salary: $490,000-$500,000.
• Born: South Africa, trained: As pharmacist.
• 1999: Completed MBA at Waikato University.
• 2003: Appointed chief executive of Otago District Health Board.
• 2007: Appointed chief executive of Southland board as well.
• May 2010: Becomes Southern District Health Board chief executive after two boards merge.
• June 2011: Resigns, effective from end of year.
• Low point: The discovery of a $16.9 million fraud of the board involving IT manager Michael Swann and his associate, Kerry Harford, between 2000 and 2006.
