"It puts the doctor in the horns of a medical dilemma."
This week Dunne approved the use of medicinal marijuana for 19-year-old Alex Renton, from Nelson, who was in an induced coma in Wellington Hospital for two months after suffering an acute seizure.
On Thursday he showed signs of consciousness. Doctors were expecting to receive a dose of medicinal cannabidiol Elixinol, from the United States, on Friday. It was not known if he had yet received any of the medicinal marijuana.
Dunne's decision was on compassionate grounds after a plea from the teen's mother.
At the same time, Prime Minister John Key said he would not support a Parliamentary debate on broadening access to medicinal marijuana because there were alternatives available.
Bennett said the soap had a responsibility to address polarising social issues.
He believed there is a "conservative antipathy" towards the use of medicinal marijuana in New Zealand which did not exist towards other powerful painkillers such as opioids, which are similar to morphine.
"There appears to be some double standards going on there," Bennett said. "Other countries have made changes towards the use of cannabis products for medical purposes, yet in New Zealand this has to go to ministerial level for sign off.
"We are not out to be judgmental on the show in any way, or saying what is happening with Pixie is right or wrong. The storyline will divide people but that is when Shortland Street is at its best."
Actress Thomasin MacKenzie said Bennett had spoken to her parents before okaying the storyline because "it is a big deal and he wanted to make sure we were comfortable".
Her mother is well-known Kiwi actor, Miranda Harcourt. Her father, Stuart McKenzie, is a writer and director.
"Playing Pixie has been intense," Thomasin said. "But the production team have really helped by talking me through the storyline.
"I have done lots of research on the internet and I have asked lots of questions. It now seems pretty unreal that just as Pixie is going through the whole marijuana story, it's happening in the headlines."
Shortland Street screens on TV2 nightly at 7pm.