A trial is underway in Saint John involving a man injured on the job 26 years ago who is now suing WorkSafeNB for $5 million in damages.
Murray Goodwin alleges WorkSafeNB abused its authority and was reckless with his claim.
Lawyers for WorkSafeNB are expected to argue that the commission should be immune from the lawsuit.
Goodwin said dealing with WorkSafeNB has been a decades-long nightmare that started in 1987.
"It's hell on earth," he said outside the Court of Queen's Bench, where the trial began Monday.
Goodwin first spoke to CBC News about his case in February, after years of decisions and appeals.
He said while working a tugboat in heavy seas, he slipped on the wet deck and fell badly.
"What happened is I broke ribs in the left side, tore my arm, pretty near came out of its socket, And the doctors said if I hadn't been strong in the upper body, I would have driven my ribs through my lungs," Goodwin had said.
Goodwin contends he was repeatedly denied treatment and surgery recommended by doctors.
Lawyers for WorkSafeNB declined to comment on Monday, referring CBC News to the WorkSafeNB communications department, which, in turn, declined to comment while the matter is before the courts.
But the defendant's pre-trial brief cites the Workers' Compensation Act, which gives the commission exclusive jurisdiction to determine disability, and says decisions of the commission shall be final, not open to question or review in court.
Last winter, dozens of injured New Brunswickers came forward to tell their stories about dealing with WorkSafeNB.
Many said they'd been forced back to work too soon or were forced into treatments in rehabilitation that caused more damage than good.
Goodwin's lawyer, Eugene Mockler, said his client is fighting for all of them.
"He is hellbound to do it on behalf of himself and many, many, many other people who have complained about the actions, or the of lack of actions of Workers' Compensation," said Mockler.
On the heels of a CBC series on WorkSafeNB, the New Brunswick government announced a comprehensive review that will take three years to complete.
Goodwin's trial is scheduled to last two weeks.