Coroner Rod Chandler was sharply critical of the mine for failing to conduct an adequate review of ground support following earlier rockfalls.
He concluded he could not "positively" find Knight's death in a rockfall on Anzac Day 2006 would have been avoided had the mine undertaken an adequate risk assessment following major rockfalls in October 2005.
Mr Chandler was also scathing of Tasmania's mine-safety watchdog, Workplace Standards Tasmania, which did not investigate the rockfalls in 2005.
Mr Knight's widow, Jacquie, was too upset to comment after the decision.
But his brother, Shane, expressed his disappointment, before vowing Larry's death would "not be in vain".
"I'll continue doing whatever I can," he said.
"I believe the actions of the mine were responsible for Larry's death.
"I believe Larry, Brant and Todd should never have been sent in to the 925m level, knowing the ground conditions to be as they were."