Justices William Young, Mark O'Regan and Ellen France found that including in the report an opinion as to the risk of re-offending such as that written by Gilmour was open to the principal case manager.
"We are, however, also of the view that the principal case manager was entitled to form a judgment as to what should be included.
"If she disagreed with the appropriateness of [Gilmour's] contribution, she was not required to include it."
The judges noted that the Court of Appeal had concluded that the content of the report was up to Corrections to determine and that there is no requirement to include any assessment of risk.
The Supreme Court said that the point at issue was extremely narrow and there was "insufficient scope for doubt" as to the approach adopted by the Court of Appeal to warrant granting leave to appeal.
The risk assessment was about the prisoner Rere Topou Pumipi. Pumipi was subsequently released on parole in July 2014 and recalled months later after assaulting two people. Pumipi was then ordered to serve his full sentence of four years and three months for what the Parole Board has described as "serious and gratuitous violence".
His sentence expired in March.
Gilmour's opinion that the prisoner posed an undue risk to public safety was in the section deleted.
The Supreme Court ordered that Gilmour pay Corrections' costs of $2,500.
A Givealittle page set up by a friend to help with Gilmour's legal costs ran for four months last year and attracted seven donations amounting to $289.
Gilmour's lawyer, Warren Templeton, said he had yet to discuss the decision with Gilmour.