Both stepped back from the train and were left standing on the platform as the train departed with all 12 passenger doors along one side of the train open.
Twelve passengers were on board at the time.
Normally, the train manager would have pressed a "right-away" button on the door control box once all the doors had closed, signalling to the driver by way of a buzzer and a light that the train had been cleared to depart.
However, the trainee prematurely thought he had heard the buzzer, so he applied power and the train departed. He failed to notice that the "all-doors-closed" light on his control panel was not illuminated.
No one was injured and there was no damage to the train in the incident.
A door-status light in line with the more conventional system of separate green and red lights to indicate safe and unsafe conditions respectively would have been more appropriate than the dated system in place, the TAIC said in their report.
The train manager was not carrying a portable radio that would have allowed her to talk to the driver, despite the TAIC previously recommending they be carried. Has she been, it could have been used to stop the train, the report stated.
A submission from Greater Wellington Regional Council which said the Ganz Mavag trains were due to be withdrawn from service within two years was accepted by the community.