Owen Curran, 67, was charged with three counts of negligence under the Safety and Health Act of 2005.
Mr Curran was running a site in Milford in Co Donegal on January 8th, 2007 when Francie Callaghan died after being hit by a digger bucket while loading concrete manhole covers.
The Health and Safety Authority claimed Mr Curran was negligent on the day that Mr Callaghan died at Forquar, Milford.
It claimed that Mr Curran, of Lower Dore, Bunbeg, had devised a method of using chains to lift the 875kg manhole covers with a digger and place them in another location.
The prosecution claimed that if this method had not been in place then Mr Callaghan of Shanagh, Fanad, would never have been under the bucket and been hit.
“If the bucket fell and nobody was below it we would not be here today. But the fact is that the system of work in lace led him to being struck by the bucket and not being here today,” said prosecuting barrister Patricia McLoughlin.
However defence barrister Peter Nolan said the reason Mr Callaghan died was because a safety pin connecting the digger bucket to the arm of the machine had not been in place.
The driver of the digger, Dermot Boyce, has already pleaded guilty to various other charges.
Mr Nolan claimed the case against his client should never have been brought and that it was an afterthought by the HSA.
“We do not live in an ideal world and things like this happen. But I would ask the jury to use their common sense.
“The reason this man died is because the safety pin was not inserted into the bucket and it came loose. My client cannot be held responsible for that,” he said.
After deliberating for almost an hour, the jury returned a unanimous not guilty verdict on all three charges against Mr Curran.