The death of Peter Watson was "an accident waiting to happen", the jury has been told in the trial of Wodonga company Bradken Resources.
Prosecutor Andrew Palmer delivered his closing address on Monday as the trial entered its third week at Wangaratta Magistrates Court.
He asked jurors to use their common sense and practical life experience to decide if Bradken could have foreseen what would happen at the foundry on the night of July 22, 2014.
Mr Watson, 42, died after a 300-kilogram metal casting fell directly onto him from the bucket of the skid steer loader he was operating, setting the machine on fire.
"Using the skid steer has risks to it, using the skid steer for hot castings was unsafe," Mr Palmer said.
"There's something that could have been done to reduce that and we say that is the use of an excavator."
Bradken has pleaded not guilty to a charge of failing to provide a safe workplace, but Mr Palmer argued there was enough evidence for the jury to reach a guilty verdict.
It was conceded that figuring out exactly what happened on the night would just be "guesswork" because there were no witnesses.
"We don't know and we can't know what the height of the bucket would have been just before the incident," Mr Palmer said.
"We don't know if Mr Watson did something with the controls in a panic."
Collin Pumpa had been working the night shift with Mr Watson when he saw the flames.
"He knew right away something had gone wrong with the skid steer," Mr Pamer said.
He reminded the jury of evidence from other employees, who had told the court of past incidents where sand or smaller pieces of metal had fallen back onto the windscreen of the skid steer loader.
"The company was on notice," he said.
"Maybe a casting could too."
Mr Palmer said the prosecution's expert witnesses agreed the skid steer loader was unsuitable for the task and its "rock-back effect" meant it was possible that if the machine ran into a clump of sand in the floor, it could have rocked back and flicked the metal casting out of the bucket and onto the operator.
"Obviously the casting did come into the cabin, it's a fact," he said.
"It shows there's a risk."
Barrister to reject evidence of expert
The case against Bradken Resources could come down to whether the jury believes the evidence of the prosecution or defence expert witnesses.
Prosecutor Andrew Palmer said his engineer and WorkSafe investigator were "clear, simple and unevasive", which was in contrast to the defence's expert Roger Kahler.
He said when he resumes his closing address on Tuesday, he would be "strongly critical" of Mr Kahler's lack of impartiality and objectivity.
"I will be inviting you to reject his evidence," Mr Palmer told the jury.
"We have two very different sets of witnesses who gave evidence and it's up to you which you prefer."
He said Mr Kahler did not complete comprehensive testing before concluding that Bradken could not have foreseen that the metal casting could have fallen onto a skid steer loader operator.
Bradken's defence team will give its closing arguments to the jury later on Tuesday.
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