"If it had rolled on the other side, those seven passengers would have been gone."
Nomad Safaris director David Gatward-Ferguson said the customers and driver were shaken but generally uninjured with no one needing to be hospitalised.
"The vehicles were heading in to the vineyard when a very large lorry emerged from a blind corner coming from the vineyard."
While the vehicle tried to reverse along the road a rear wheel mounted a bank and tipped over.
Nomad Safaris is a tourism company offering small, personalised tours into the New Zealand back country.
Tour routes incorporate sections of Lord of the Rings filming locations and Otago gold mining settlements.