Kevin McCoy said Friday that the company imposed the 30-day suspension because of a problem with Peter MacKenzie's inspection of scaffolding.
McCoy said MacKenzie's death is a tragedy and he has expressed his condolences to the family. But he denies accusations by some union members that MacKenzie was bullied by the employer, saying it's not possible to link his death to the suspension.
"I would never guess as to why people choose to take their own life," he said.
He said the suspension occurred because of problems with the way MacKenzie inspected staging, adding that strict standards must be followed to preserve the safety of all employees who use the staging while working at the shipyard.
"Staging is one of the areas that has to be done absolutely right every day," he said.
"When we look at discipline, we take a very measured approach. We look at the employee's work history, we look at previous issues, we subject it to previous management review. ... In the end, we take the action we think is right for the workforce as a whole."
McCoy declined to specify what MacKenzie did incorrectly.
The RCMP say the man's death is under investigation but it appears to be self-inflicted.
About 200 workers at the shipyard walked off the job Thursday morning after hearing of MacKenzie's death, saying he was unfairly disciplined.
McCoy said he understood the workers were upset about a beloved co-worker.
"It was a high emotion day and I think it was difficult for them to deal with and some chose to leave in response to that emotion," he said.
Some workers have also said that the number of disciplinary actions against employees has increased since McCoy became president in the summer, adding that they believe some of the suspensions and firings weren't necessary.
McCoy said there have been seven firings in the past year and they were justified.
He said five of them were the result of violence or threats of violence in the workplace, one was a case of a worker who didn't pass probation and another involved the use of a controlled substances inside the shipyard.
Cliff Pickerim, the president of the Unifor local, said talks on the issue of discipline have been held with management since the walkout.
Pickerim said the two sides may set up a committee to deal less formally with disputes, outside of the traditional grievance process.
In 2011, the shipyard won the bid to build Canada's next generation of surface combat vessels. As part of that process, it negotiates individual contracts with Ottawa on the construction of the ships.