The public inquiry is looking into the June 2012 mall roof collapse, which killed two women.
Last week, the inquiry heard a chunk of concrete from the ceiling fell into the kitchen of a restaurant in the mall, just months before the fatal cave in.
Bruce Ewald, Elliot Lake's chief building official, was questioned about the incident during his testimony Monday.
"Can we agree that pieces of concrete falling from the roof of the mall show a structural problem," asked commission lawyer Peter Doody.
"No," Ewald replied.
"It could be indicative," Ewald continued. "It very well could be a sign of that, but it may not be as well."
Ewald told the inquiry he did not investigate further. He admitted, in hindsight, there was a structural problem at the mall.
'I would close it'
Ewald was also questioned about concerns raised by Elliot Lake city councillor Al Collett, who testified earlier.
- READ: Concrete fell months before Elliot Lake mall collapse
Collett testified he told Ewald about the concrete that fell from the ceiling, but was told dealing with the mall was a difficult issue because closing it would make the city look bad.
Ewald clarified his response for the inquiry.
"What I had said was 'what do you want me to do Al? Close down the mall?' It was a flippant remark on my part."
But Ewald went on to say closing the mall "would have been economically detrimental to the city ... However, if I had evidence that there was a structural issue that required the mall to be closed, I would close it."
Hearings continue through summer
The inquiry was established in July 2012 by the Ontario government to report on events surrounding the mall roof's collapse, and the deaths of Lucie Aylwin and Doloris Perizzolo, as well as the injuries to others and the emergency management and response.
Hearings began March 4 and are expected to conclude with testimony from former premier Dalton McGuinty on Sept. 12.