Christchurch surgeon Phil Bagshaw, who carried out the review with gastroenterologist Dr Steven Ding, said yesterday opinions had become so polarised over the issues the situation would "end up in deadlock".
He will be raising the matter with Health Minister David Clark.
The most important question for a public inquiry would be why the Ministry of Health allowed the board to go ahead with bowel screening when ministry statistics showed it was "too cash-strapped to deal adequately with patients with advanced bowel cancer".
Mr Bagshaw made these comments when asked his opinions on a leaked letter from the New Zealand Society of Gastroenterology raising concerns over issues aired in the report and demanding immediate action on them.
As a past-president of the society, in the 1990s, Mr Bagshaw said it was rare for such societies to "write strong letters of this kind".
Mr Bagshaw said it was clear the board was "absolutely struggling with inadequate resources" and the questions raised by the society around training were an indication of that.
He repeated his disappointment at the board's response to his report, describing it as "just window-dressing".
The board says it has aligned its processes for accessing colonoscopies at Dunedin and Southland Hospitals, and will be organising a review of 102 cases where questions have been raised about patients' diagnosis or treatment and comparing them with a control group.
In the past, it has defended its decision to join the national bowel screening programme, saying it had been meeting waiting times for diagnostic colonoscopies.
The Bagshaw/Ding report found diagnosis was delayed in 10 of the 20 cases it reviewed.
The terms of reference for the report stated the SDHB would consider the recommendations and take all reasonable and practical steps to either implement them or make it clear where recommendations were impractical or impossible.
The board has yet to respond to a media request to show what it had decided to do on each recommendation.
Mr Bagshaw said his request for that information was met with the response: he had done his job and a question: how much did the board owe him.
He said he had earlier suggested a koha to his charity hospital, but later made it clear he wanted neither payment nor a payment to the charity.
