"We had some schools where parents were banging on the doors, sometimes threatening people, trying to take their children out of the school, which of course means we have to open up the doors to let them in so obviously that goes against what a lockdown is," he told the radio network.
"It is one of the bigger problems, so we just need to have confirmation and direction that says the police have put us into a lockdown, then they are the ones who lift it, and that means that everyone stays away."
Casey said schools, kura and early learning centres "did the best job they could of keeping their children safe in very challenging circumstances".
"Because this lockdown was for a significant period of time, covered a large area of a major city, affected a very large number of families and occurred at a time of uncertainty about the nature of the events that were unfolding it is even more important than usual that we undertake a review of all aspects of the lockdown," she said.
"We will be doing that review in conjunction with police and the three principals' associations and will be seeking views from parents as well.
"We expect the review will help inform appropriate advice to all schools and early learning centres.
"The review will get under way from April 2 and will take at least a few weeks to complete. We are also mindful that the term break will shortly occur and we need to ensure everyone who wants to have input can do so."
Terms of reference for the review will be made available on April 2.
