Council city property manager Robert Clark yesterday said that could lead to a laminated layer being added to the mall's roof, or to the installation of transparent netting underneath, to ensure the area remained safe.
The two suggestions came after Mr Clark met a visiting Australian commercial construction quality manager yesterday, one day after the man told the Otago Daily Times there was a risk Wednesday's incident could be repeated.
The man - who would not be named - blamed the incident on "nickel sulphide inclusion", which could occur during the manufacture of float glass that is later toughened.
Nickel contamination meant nickel sulphide crystals, formed during glass toughening, slowly reverted to a larger form, expanding to trigger shattering.
Mr Clark said after yesterday's meeting he remained confident there was "no real immediate danger" of a repeat, but the exact cause had not yet been confirmed.
"It is a possibility that it could be this nickel sulphide [inclusion] situation. At this stage we just don't know, but we are still taking the matter seriously and we will still work through a process to make sure that it is safe."
The Australian-based manager was a former Dunedin man back in the city on holiday.
He offered at yesterday's meeting to put Mr Clark in touch with another Australian glass specialist, an offer Mr Clark had accepted, and the pair would discuss the Wall Street situation by telephone next week.
Mr Clark ruled out the need to re-roof the mall, but said a "simple solution" - possibly involving lamination or netting - might be considered, depending on what inspections next week revealed.
Any engineering solution wouldn't cost "a great deal of money" and could be completed in weeks or months.
Mr Clark joined the council about six months before the council-owned $34 million Wall Street mall opened in March 2009, but said he had no concerns about design decisions made before his arrival, and did not think decisions made about the use of glass were influenced by cost concerns.
The glass - like the rest of the building - met New Zealand standards, he said.
"We may have done a few things differently but certainly I don't think I would have picked up the glass situation ... You have to rely on experts to do those sorts of things."
