"Knowing how to 'go there' and deflate that balloon gently is part of the art of being a good teacher," he said.
He said it was hardly ideal if teachers were tearing their hair out over something they wanted to say but felt unable to. "Parents deserve honesty," he said.
"The openness of the dialogue between teacher and parent is really important."
Quality education involved the child, teacher and parent, Reynolds said.
"One of the most critical jobs anywhere on the planet is parenting. It comes without a job description or a guide book to tell people how to do it. It can be harshly challenging and tremendously rewarding.
"Teachers understand this. The teacher isn't there to tell the parent how to parent, but to assist and support the parent to make sure the child has every opportunity to develop and prepare for life."
Home educators share preschooler tips
After 16 years in the early childhood sector, Allana Mills knows a thing or two about preschoolers.
She looks after four children at her Mt Eden home every day, and has done so for the past eight years as a Porse home-based educator. She says the secret to a successful relationship with parents is open communication.
"We have a shared understanding," she says of her relationship with Jacqui Deheer, mum of 2-year-old Ted, one of Mills' charges. "We're pretty laidback with each other, she's a very relaxed mother. She really trusts me with Ted."
Deheer appreciates Mills' skills and says she has picked up many pointers from her. "Definitely. You see how she deals with the children, and you do learn a lot."
Ted's days with Mills amount to much more than a childcare arrangement. "You actually have time at the beginning and end of the day to chat as she's not having to watch 10 other children," Deheer says.
So does Mills have advice for parents?
"It doesn't apply to any families that I have worked with," she says, "but people see the lack of language in newborn babies as a lack of intelligence. Babies take everything in without discrimination.
"What's really important is what you introduce to them - you can change their life."