Former Police negotiator Lance Burdett believes turning the garden sprinklers on protesters was a mistake, creating an environment where those camping out on Parliament grounds became resolved to stay at all costs.
The Speaker of the House, Trevor Mallard, had sprinklers turned on overnight as the protest entered its fifth day in an effort to clear the grounds.
He had hoped the lawn sprinklers would soak the lawns underneath tents.
However, protesters used road cones and their hands to dig trenches in the mud to divert water away from their campsites.
They also brought in hay to cover the muddy ground.
"That was an error," Burdett told the AM show. "They pushed back twice as hard."
He said it also meant people outside the protest movement had sympathy for the cause.
At that stage, he said, there was a solid group of core people that were there to say "we're here and you're not listening and please listen".
Burdett said the decision to turn on the sprinklers was, from what he understood, done outside police control.
He said police would know that if you did those sorts of things it would cause an affront.
Another problem was that as the protest drew out, no one was there to talk to them.
"I would expect the Prime Minister not to talk but somebody senior from the group could have gone down and spoken with them."
He said it was an opportunity for the Government to tell them that they were looking at reducing mandates anyway.
Hastings Rd is closed for a Serious Crash Unit examination.