A sacked Aldi store assistant who used AI to make a “just plain wrong” argument he was unfairly dismissed has been forced to pay $1230 toward the supermarket’s legal costs in the first ruling effectively punishing a former employee for wasting the Fair Work Commission’s time.

On Wednesday, the country’s workplace umpire, which has highlighted the rise of nonsensical AI-generated applications that have led to an explosion in its workload and slowed down its processes, said the latest case involving AI was one with “no winner”.

The case is a sharp contrast to a victory for a Macquarie University worker who used AI successfully to become the first casual employee to win orders from Fair Work last week converting him to permanent part-time status, over the opposition of the educational institution’s lawyers.

Wednesday’s case shows a new potential pitfall for workers who rely on AI in making their claims in Fair Work, despite the jurisdiction originally being set up as a free forum to help employees.

Fair Work Commission deputy president Michael Easton said the Sydney Aldi worker, who had used AI extensively to start and continue his unfair dismissal claim, had acted ignored multiple warnings he might have to pay costs and pressed ahead with his claim when it was clear he could not win.

“I have taken the very rare step of ordering [the man] to pay some of the employer’s legal costs because his unreasonable conduct caused his former employer to incur those cost unnecessarily,” Easton said.

Crucially, the man was not eligible to make an unfair dismissal claim because he had not served the minimum employment period of six months.

He had been dismissed on a date three days short of the minimum requirement, but his AI-generated materials had, from the beginning of the application process, focused on a “different and irrelevant date” according to the judgment.

A week before the hearing was due, Easton reviewed the materials filed by both sides and decided the man’s case was “hopeless” because it failed to meet the eligibility requirements.

The initial application filed by the man was “obviously prepared using AI” Easton said, containing AI drafting notes including: “Here is your final clean copy-paste version, with today’s date inserted as the dismissal date.”

“I took the time to write to [the man] and explain to him well ahead of the hearing, in plain English, why his case was unlikely to succeed,” Easton said. “[He] was encouraged to discontinue his application, and advised that there could be costs consequences if he continues his claim.”

The man’s AI-generated email reply once again addressed the wrong end date, Easton said, and repeated the same irrelevant AI-generated arguments.

“I took further time to send [the man] another email in the hope everybody’s time and costs would not be wasted by attending a hearing,” Easton said, stating in “much stronger terms” the “very strong likelihood” that his case would not win and that he would have to pay Aldi’s costs, after it applied for compensation.

The man continued his case and sent two further AI generated submissions that again addressed the wrong end date, Easton said.

It was not until the hearing, where Easton raised the same concerns, that the man, for the first time, agreed that he had not completed the minimum employment period and decided to discontinue his application.

However, the man tried to argue he could not reasonably have been expected to understand the distinction between the date he was notified of his dismissal and the date the dismissal took effect because he “is not a legal expert.”

Easton said the man’s submission was “not complete AI slop, as that term has come to be used,” in that some of the legal arguments presented were “more or less correct, though irrelevant”, and the High Court cases cited were real cases rather than hallucinations.

However, he said the submission still focused on the effective date of the man’s dismissal, which was labelled as being “unresolved” despite there being “no doubt” about it.

The man was ordered to pay $1230 in legal costs Aldi wasted in preparing for and attending a hearing that, according to Easton, “should never have taken place” with losses for both parties that were “utterly preventable”. That represented a small part of Aldi’s overall costs, Easton noted.

Easton said that had the man read the emails from the commission himself, he would have realised the “unfixable flaw” in his case.

“[The man] could have and should have chosen to cut his losses when he had the chance,” Easton concluded.

Aldi was contacted for comment.