Police decisions to pursue are complicated and made quickly under pressure, the Police Association president says, and an upcoming report is not likely to solve the problem.
Police pursuits are under the microscope given several high-profile police pursuits that ended in driver deaths.
Police said they abandoned pursuit before the car hit road spikes and crashed into a tree about 11.13pm.
Officers tried to help the teens but could not, and were themselves injured, police said.
Police Association president Chris Cahill said an upcoming Independent Police Conduct Authority (IPCA) report would not provide a silver bullet to the complicated issue, but he was keen to see what the IPCA thought should change.
"I think yesterday's tragedy really shows how complicated these issues are," Mr Cahill said.
"It's not simply a matter of saying that police should not pursue. We've seen that in this case, and often it's the case that the driving was dangerous before the police were involved and it continued to be dangerous after.
"It's really hard, getting that balance right, and that will always be the problem.
"We'll be very interested to see what information they've managed to pull together and how that adds to the debate but we don't think there'll be a silver bullet in this."
Mr Cahill has long experience policing New Zealand roads, and said the way pursuits were dealt with had changed dramatically.
"I mean, when I was a young police officer we would pursue for kilometres on end and there would be multiple police cars," he said.
"That situation has changed dramatically now. Specialist drivers should be involved, specialist vehicles if available, and most pursuits now only last a matter of seconds."
Road police are trained to make a quick risk assessment before pursuing a driver.
It can be difficult to make that assessment in a split second, and Mr Cahill said police are being judged in these cases on a decision that is incredibly hard to make.
"Something can happen two blocks down the road, and you'll be judged on your call in hindsight," he said.
"That's the problem with policing in these things.
"It's hindsight that people judge you in when you've got to make these split second decisions and things change so quickly."
The IPCA has been notified of Sunday's crash and will be investigating.