"He was trying to do it up and make some money and I think he was looking into some other areas, but then it all kind of just came to him in the end."
On April 21, 2009, a Westpac worker mistakenly increased the overdraft limit to $10 million instead of the approved $100,000.
"I'm f***ing rich, I've got $1 million," Gao was heard to yell amid excited hoots when he saw the extra zeroes on the screen of his laptop.
Over the next few days, he made a series of transfers to various accounts through six remittance companies, before leaving New Zealand on April 29.
Hurring followed soon after.
After more than a year on the run and the birth of a baby boy, the couple were arrested separately last year.
Mr Levaillant was not surprised that Gao - who was reportedly working in Shenzhen as a financial clerk when he was caught - had orchestrated such a complicated swindle.
"He seemed like a bit of an on-to-it, smart guy and I'm not surprised he took it.
"He was always looking for an opportunity - he would have taken it and he did.
"He was one of those quiet people, that once you get to know them then you find out they are thinking a lot more than you thought they were."
Gao's former flatmate Bianca Taute, who was home the night Gao discovered the millions, also remembered him as a quiet, seemingly normal man who often worked nights.
The greying Gao who yesterday arrived at Auckland District Court wearing jeans and a blue dress shirt appeared much older and tired than the man Mr Levaillant knew three years ago.
For reasons that are suppressed, the 16 charges he originally faced, which included two money-laundering charges, were changed to seven counts of theft.
He has been remanded on electronic bail until his sentencing in Rotorua on August 24.
But Judge Roy Wade said bail did not mean he would necessarily avoid prison.
Gao refused to comment as he left the court.
His guilty pleas come after 33-year-old Hurring - who claimed she had been under the impression Gao had won Lotto - was found guilty on 30 charges.
It remains unknown what happened to most of the HK$1.5 million ($250,500) that Gao deposited into a VIP player's account Hurring opened at a Macau casino.
The court is seeking an order for Gao to repay close to $3.8 million Westpac has been unable to recover, and the Herald understands the police investigation has now finished.
OVERDRAWN, THEN ROLLING IN MILLIONS
* April 19, 2009: Leo Gao applies to Westpac Bank for a temporary overdraft.
* April 21: Clerical error sets Gao's overdraft at $10m - $9.9m more than the $100,000 approved.
* April 24-29: Gao withdraws $6.7m. Most is channelled into overseas accounts in China and Hong Kong.
* April 29: Gao leaves for Hong Kong.
* April 29-May 3: Gao's partner Kara Hurring makes multiple transactions on an ATM card loaded by Gao, then follows him overseas.
* May 4-6: A tip-off alerts Westpac, which eventually manages to recover $2.9m. $347,460 is transferred to a casino in Macau, converted into HK$1.5m and deposited into account opened by Hurring. HK$1.4m vanishes.
* August 9: Westpac worker responsible for mistake sacked after another error. No cash lost this time.
* February 25, 2011: Hurring arrested after returning to New Zealand.
* September 30: Gao apprehended in Hong Kong.
* December 21: Gao escorted to NZ and arrested.
* May 18, 2012: Hurring found guilty on 30 charges after a four-day trial.
* Yesterday: Gao pleads guilty to an amended indictment of seven theft charges.
* August 24: Gao and Hurring to be sentenced in Rotorua.
