The plan does not specifically mention adverse weather conditions trigger the use of over-snow transportation.
DoC spokesman Bhrent Guy said RAL was allowed to use snowcats because it fitted within the parameters of the management plan.
The shuttle was run between ski area buildings - a cafeteria and a kiosk - and was therefore acceptable.
He also said safety was a factor in the decision as the recent rain storm had washed snow off the mountain, making it unsafe to access the Far West T in the usual way.
"Basically what was happening was that both ice and the track washout meant that people wouldn't be able to get backwards and forwards."
Mr Guy said the licence was only for a limited period of time.
"This won't be a carte blanche licence to go out and use the snowcats to transport people willy nilly," he said.
Mr Guy would not rule out allowing RAL to use snowcats in the future.
"If this should happen again then they would make application to the area manager who would consider the request in terms of public safety."