Retired gaming consultant John Stanley Beagle, 83, launched a civil case against the rugby club, arguing he should have been paid a finder's fee for the record $8 million deal struck with developer Aquis, owned by the billionaire Fung family.

Mr Beagle claimed he helped connect the Brumbies and Aquis shortly before the company announced its purchase of Canberra's casino. He had not entered into a contract and said he was never paid.

He sued the rugby club in the ACT Supreme Court, claiming "reasonable remuneration for work done and services provided".

But Associate Justice David Mossop on Friday ruled in favour of the Brumbies, finding Mr Beagle's efforts hadn't "had any positive causal effect on the ultimate transaction".

During a court hearing last month, barrister Doug Hassall argued Mr Beagle had performed services requested by the Brumbies, with the understanding he would get paid.

He said those services assisted and enabled the sponsorship deal, leading to "massive benefits" for the two parties, and argued it would be unjust for the Brumbies to retain those benefits without proper compensation for Mr Beagle.

Dr Hassall said his client was involved with a series of incidents to help clinch the deal, including an early meeting with Brumbies executives where they discussed making presentations to Aquis senior managers.

He claimed he also pitched the deal, at the Brumbies' request, to Aquis management, and later briefed senior executives at the rugby club on the dynamics and Australian business interests of the Fung family.

Mr Beagle's lawyer argued his client carried out services "of considerable value" and it was clear he expected to be paid for his work.

However, lawyers for the Brumbies, led by barrister Richard Arthur, said there had been no formal agreement Mr Beagle would get paid.

They said he had offered some "introductory insights" and there was no evidence he had remained involved after the Brumbies took a primary role in the deal.

Associate Justice Mossop said although it appeared Mr Beagle was the first person to make a direct connection between Aquis and the Brumbies' sponsorship, that alone wasn't enough to show his services materially contributed to the eventual deal.

"In my view, if the position is that Mr Beagle objectively made no causal contribution to the obtaining of the sponsorship then the mere fact that a sponsorship arose is not sufficient to give an entitlement to remuneration."

He found it wouldn't be unjust for Mr Beagle not to be paid, partly because his services "involved a kind of speculative effort undertaken in order to test whether an opportunity can be realised" and had no market value.

"The contribution of Mr Beagle had no causal effect upon the obtaining of sponsorship either by planting the seed of an idea or positively assisting with the process leading to the ultimate deal.

"Thus, it cannot be said that the benefit obtained by the Brumbies was a material contribution to obtaining a very valuable sponsorship."

The case returns to court for a costs hearing next week.