Jack Hoffman says he was left mentally damaged after he lost his job at Canberra's deep space research station after being caught using work cars to grab a burger and fries from a Macca's drive-through.

But Mr Hoffman, who also featured in the "lollygate" controversy" at the famous research facility, remains defiant, saying he is another victim of abuse of power in the public service.

Mr Hoffman was on his last warning from his bosses at the space research station in May 2012 when he was spotted by colleagues pulling into a McDonald's drive-through in a CSIRO-supplied work car.

The co-workers dobbed him in to Canberra Deep Space Communication Complex bosses and Mr Hoffman, who had been specifically warned to stop using work cars to pick up burgers, was told he was facing the sack and offered his resignation.

The previous month, in an episode dubbed "lollygate" at the research station, bosses banned lollies from the workplace after Mr Hoffman lodged a workers' compensation claim after breaking a tooth on a CSIRO-supplied sweet.

After his sacking, the former NASA technician unsuccessfully pursued unfair dismissal proceedings at Fair Work Australia and lodged a new claim for workers' comp for "adjustment disorder with mixed emotional features" caused by his termination by the CSIRO.

But federal workplace insurer Comcare refused to pay and the matter ended up in the Administrative Appeals Tribunal in Canberra in October.

Comcare did not dispute Mr Hoffman's case, backed by medical evidence, that the technician had developed mental health problems as a result of the events of May 2012 but the insurer argued the CSIRO's actions had been reasonable and taken in a "reasonable manner."

At the tribunal hearing in front of AAT deputy president Katherine Bean, Mr Hoffman's lawyer David Lander argued his client's bosses should have taken his food addiction into account when deciding on disciplinary action over the drive-through incidents.

Mr Lander also told the tribunal that Mr Hoffman had become a difficult or "problem" employee, and the research station's managers were effectively looking for an opportunity to get rid of him.

But Ms Bean backed the actions of the science organisation, noting that Mr Hoffman knew he should not have been using the work car for McDonald's runs and that it was not an isolated incident of misconduct.

"He clearly knew that stopping at the McDonald's drive-through on his way home was a breach of the policy, and decided to do this anyway, presumably in the hope that he would not be 'caught'," the tribunal deputy president wrote.

"It was part of a pattern of conduct by Mr Hoffman, involving problematic behaviour in the workplace and refusal to follow directions from his superiors."

In the wake of the decision, Mr Hoffman remained defiant, telling The Canberra Times he was the victim of a vendetta by his bosses playing out against a background of widespread injustice towards workers in the Australian Public Service and the broader public sector.

"The "McDonald's incident" was simply the only opportunity that came close to becoming anything close to a misconduct event that would give the CSIRO any authority to behave in the manner that they did," Mr Hoffman said.

"There is a bigger issue at play and that is the systemic abuse of government authority."