But the commission ordered an employer to compensate another worker who told his boss to "shove his roster up his arse".

A hydraulic hose technician employed at Steelcon Cava was involved in a scuffle with his boss after a disagreement about whether the company was paying for his food at a caravan park mess hall. The worker said he understood that he was entitled to free meals, but the employer argued this was never the case.

The worker alleged his boss started yelling at him and telling him to "f--- off, you're finished here, get out of here".

It was alleged the boss then pushed his chest into the technician who later said "kiss my arse", while pointing to his rear end. The employee packed up his tools and left.

The worker said his boss effectively terminated his position during the heated argument. But the employer said the technician voluntarily resigned and did not withdraw his resignation.

Senior Deputy President Peter Richards said that on the balance of probability he preferred the general manager's evidence, which contradicted the worker's version of events.

The technician's diary entries about the incident were dismissed as unauthentic and CCTV footage was held to have "no probative value" because of the lack of audio and because the camera was too far away from the exchange.

Mr Richards said the technician's evidence "causes me to conclude that he was not dismissed at the initiative of the employer, but rather resigned his employment in a moment of pique".

He said the general manager had reasonably relied on the worker's conduct to assume he had "voluntarily ceased to be an employee at his own volition".

In another case before the Fair Work Commission, a worker who told his boss to "shove his roster up his arse" had not been shown regard for his disability.

Test-Rite Imports Australia, which trades as Medalist, dismissed the casual storeworker in October last year, a day after his supervisor provided instructions on correct use of a mechanical sweeper and he had allegedly responded by telling him to "shove his roster up his arse".

The casual store worker, who has cerebral palsy, was on a supported wage as a result of his disabilities.

"There have been a lot worse things said by an employee to an employer representative which have not led to dismissal. There was no evidence of anger or aggression," Deputy President Jeff Lawrence said.

"I am satisfied that the applicant's words, in the context in which they were spoken, do not constitute a valid reason for dismissal."

The worker said his outburst was out of character, but arose from frustration after his supervisor had criticised him. He said he had been absent when the roster was changed and he had not been trained in how to do the cleaning task he was given.

The employer said it had previously given the storeworker warnings about his temper.

But Mr Lawrence found the employer had not given the worker enough regard for his disability.

Mr Lawrence said the worker was protected as a casual employee under the Fair Work Act and ordered he be paid $3850 in compensation for his unfair dismissal.