The boy was held for a time by an adult and dangled for two minutes while rescuers rushed to the slope below.
They used safety pads to create a makeshift net, and the boy was safely caught after falling.
Mt Hutt Ski area manager James McKenzie said the boy appeared to have wriggled out of the new eight-seater chair's safety bar.
"The child was riding a lift with two other children and an adult and the adult has told us that the child had successfully sat correctly on the chair," he told Morning Report.
"But at some point there's been a bit of manoeuvring as the safety bars come down and the child has managed to twist his body - the safety bar has come down between their legs as a foot rest - and the child has managed to swivel their legs to the side and, at that point, the child has started to slip."
McKenzie said such incidents were rare and the new chairlift was not that different from other older chair lifts.
To avoid similar incidents those supervising small children must ensure instructions were followed correctly, he said.
The rescue operation took approximately two-and-a-half minutes and other guests riding the lift were not stuck for a significant period.
Safety patrollers would continue to be located around the mountain as thousands were expected to visit during the school holidays, he said.
