The man rips the flag from the hood and walks back to his vehicle.
Another video taken last night shows a large group of people, some holding Samoan flags, swooping in on a vehicle where it appears someone is being attacked.
Other Samoans step in, shouting for the attacker to stop.
There is shouting and glass can be heard breaking in the background.
The police said the vast majority of fans have entered into the spirit of the Rugby League World Cup, but are disappointed by incidents of disorder at some gatherings.
Superintendent Sandra Manderson, National Commander Major Sporting Events, said it has been great to see the enthusiasm shown by fans in the lead up to the Tonga-Samoa match in Hamilton on Saturday, but some people have taken it too far.
"We want everyone to have a good time, but we won't tolerate people behaving in a way that spoils it for others," she said.
There are also concerns about the unsafe behaviour exhibited by some on the roads.
"It's great to see people getting behind their team, but it's really important that people don't put themselves in positions that risk their safety or the safety of others.
"Walking into traffic and blocking busy roads is never a wise thing to do, and riding on top of moving vehicles is extremely dangerous. Even if a car is moving very slowly, someone who falls off could be very badly injured, especially if they're hit by the car they were on or another one on the road," Manderson said.
Police are also reminding people who are travelling to the Tonga-Samoa game in Hamilton to take care on the roads and leave plenty of time for their journeys.
"There are a number of events in the region over the weekend, so we're expecting traffic to be heavier than normal. As usual, people should factor in the potential for delays, not drive after drinking, drive to the conditions and ensure everyone in the vehicle is properly restrained," said Manderson.
"We're also asking fans going to the match to not travel in convoy as this can add to any delays and be frustrating for other road users."