John Wilson died Feb. 28, 2008 at the Craigmont Mine when the excavator he was operating overturned in a reservoir filled with water.
The branch says that based on evidence submitted by the RCMP, prosecutors would be unable to prove a breach of duty, a wanton or reckless disregard for life or safety, or any breach contributing to his death.
Jim Sinclair, president of the B.C. Federation of Labour, said the decision shows there are two forms of justice in this province when it comes to deaths in the workplace.
"We were cautiously optimistic this might have been a change in practice by the Crown," he said.
"But this is yet again another example where the Crown rejects applying justice to the companies involved in deaths of workers, who we believe are open for charges of criminal negligence because of the circumstances of this case," he said.
In a statement, the Criminal Justice Branch said there was evidence the reservoir, known as a sump, was not designed by a qualified professional to accepted engineering standards, and a previously ordered survey of the mine site had not taken place.
In addition, although not legally required, the branch noted the mine did not have an emergency response team in place at the time of the incident.
However, the branch said, there was no evidence that these factors would have prevented the accident or Wilson's death.
It also says the six-month time limit for charges under the Mines Act has expired, and the Workers Compensation Act does not apply.