She was waiting outside the restaurant with about 60 other fans as he brushed past her when he was returning to his car.
"He said 'hi girls, how are you?'"
"We apologised for interfering but he said 'don't be sorry for something you haven't done'," Watherston told Fairfax.
Yesterday the singer was pictured on the Shotover Jet with his mates.
As the boat took off on its "breathtaking ride" through a narrow gorge, reaching speeds of up to 85km/h, Bieber appeared disinterested.
He continued to stare off to the side as one of the other boat patrons snapped photos with his camera phone.
The Jet-boat experience has reportedly thrilled more than 3 million people since its debut in 1965, including the Duke and Duchess of Cambridge, Ed Sheeran and Sir Ian McKellan.
It hasn't been all doom and gloom for the Where Are U Now singer after finishing his touring duties, presenting a happier picture as he enjoyed a bike tour around Auckland earlier in the weekend.
Jumping in a three-person rickshaw, Justin was joined by Hillsong preacher Carl Lentz.
Riding through the dark streets, Bieber and the group sang along to the Ludacris' Move B***h (Get Out the Way).
Bieber is staying at Sir Michael's exclusive property The Hills, which costs $32,250 a night during the August to June high season.
It is popular with pop stars. Singer Katy Perry apparently stayed there during her 2014 tour. Bieber is understood to be staying in the resort for a couple of days before flying to Santiago, Chile, for the next gig on his tour, at Estadio Nacional on March 23.
- NZ Herald, Daily Mail and The Otago Daily Times
