While well-run coal mines should never have explosive levels of gas, the risk was mitigated by not providing an ignition source.
"Pike River wasn't a result of smoking, but that's what could happen. If something does happen you're going to include all your mates in it as well."
Mr Baker was not aware that anyone had been caught smoking in a New Zealand coal mine before, but if they were they would be "appropriately and severely dealt with".
An Australian Department of Natural Resources and Mines spokesman said the sentence reinforced the importance of workplace health and safety.
"We have tough laws in place to minimise the potential risk of injury or death to workers and ensure the highest standards of safety," he said.
"Underground coal mines are difficult working environments.
"The presence of combustible gases and coal dust means there is a potential for fire or explosion if strict safety procedures are not followed to the letter.
"This person, through his actions, was not only endangering himself but the lives of his fellow mine workers."