The occasion was the last meeting of the hospital advisory committee which Mr Thomson chairs.
In typical style, he departed from the agenda to deliver a final speech, because "I can't help myself".
His "couple of comments" were greeted with a round of applause from the committee.
He warned that freed from any chairing responsibilities with the new Southern board due to come into being next month, he would be "a slightly loose cannon" who could "antagonise other chairs without setting an example".
Speaking after the meeting, Mr Thomson said at this stage he had no intention of standing for the new Southern board at the elections in October and was "99% sure" about that.
In February last year, Mr Thomson was controversially sacked as board chairman by Health Minister Tony Ryall, who said he was seeking accountability over the $16.9 million fraud of the board between 2000 and 2006.
Mr Thomson continued to serve on the board and as hospital advisory committee chairman because, unlike other district health board chairmen, he was not only a government appointee but also an elected member.
In his speech yesterday, he said there was an urgent need for the new board and hospital advisory committee to make progress on "lean systems" across Dunedin Hospital.
While some progress had been made on this last year and there was a willingness to proceed, it was not moving fast enough, he said.
He described the new board, which will contain all members of the two existing boards, as being "a bit of a dog's breakfast to start with".
That could not be helped and it was a necessary transition if "we hope to sustain clinical services down here".
Behind the scenes Mr Thomson played a leading role in helping to move the two boards together during his term as chairman.
Yesterday, Mr Thomson praised the work and dedication of Dunedin Hospital staff who had in the last four years increased the amount of surgical procedures done by the board by about 15%.
He acknowledged funding incentives to do that, but it also had to be seen in the context of the slowing of the board's overall funding and the inadequacy of some hospital facilities.
In those circumstances, the output of staff was significant and it was "important that we recognise that they could get better hours and more money in the private sector, but they still work with us".
Mr Thomson said it was essential Dunedin Hospital got its long-awaited upgrades to repay that loyalty and he hoped that would be possible this year.
He repeated previous criticism of politicians, of any persuasion, "point scoring" over the need to bring resources to the front line, an argument which he said which was often made to the "point of dishonesty".
If it resulted in hospitals struggling to get and retain strong management, it would be a public loss and politicians' shame, he said.
A good back office was needed as a part of a health services team and it was not a matter of elevating some members of the team to sainthood and demonising others.
All members had to be supported and valued.
Mr Thomson also thanked hospital advisory committee appointees Dr John Adams and Dame Norma Restieaux for their wisdom and clinical knowledge which had been of considerable benefit to the committee.
The membership of the new Southern hospital advisory committee and who will chair it is yet to be determined.
The last meetings of the Otago and Southland full boards were held earlier this month.
