"They nailed us all to a chair and really grilled us," says Magan. "It wasn't a light thing they were doing, they wanted to get to the very guts of what we were about. And they got stuff out of us we might not have thought of or discussed for nearly 50 years. It really got the old emotions going again."
As a result, the former DJ reckons the programme has "a lot of depth to it" and although he admits it's "a funny feeling seeing a bit of your life up on screen like that", he and his ex-colleagues were "all quite blown away.
"We agree they've done a great job of documenting everything and giving a true sense of the rather adventurous time we had."
He contrasts this with the feature film 3 Mile Limit, released earlier this year, which purported to be the Radio Hauraki story but took a number of liberties with facts and chronology.
"I thought it was a nice bit of entertainment but that's all you could really say for it - it wasn't really our story," Magan says.
He's quick to add that its producer, Craig Newland, is "a really good guy" whom he admires for all the years he put into bringing the project to the big screen. Some of the special effects are "brilliant", and Magan appreciates that the film-makers went to the effort of using local musicians on the sound track who were around during Hauraki's early days.
"In the end, though, when you're involved with something, you expect people to respect the history of it, which is something Pirates of the Airwaves absolutely does."
Magan is especially impressed by how director Charlie Haskell and writers/producers Donna Malane and Paula Boock "ferreted out a lot of the story" before the old seadogs were interviewed.
"That surprised me, actually, because even a lot of people who were there at the time didn't know the inside story."
He was initially less enthusiastic about the use of Hauraki DJ Rick Grant - who died shortly after the station was finally granted a licence - as the narrator who ties together the dramatised scenes with the documentary content.
"When I first heard about that I was a little bit dismayed and suspicious," he says. "But when I saw how they'd done it I thought it was absolutely bloody brilliant. He was such a big part of the story, so to have him coming and going and telling it in his own way was very clever, and a great tribute to him.
"Had Rick lived I'm in no doubt he would have been the foremost broadcasting personality of his time, he was that good. He'd have gone on to be another Paul Holmes, on radio and television, because he was good looking, had a strong voice, a great personality, and a great knowledge of music and current affairs."
When Radio Hauraki first took to the high seas, says Magan, "most of us were optimists and thought we'd clean it up in six-to-eight months. Instead we spent 3½ years having no idea of what the next day would bring."
Magan acknowledges the crucial role Derek Lowe and David Gapes played in keeping the crew together during that uncertain time.
"David just lived and dreamed it and only had to say, 'I want to do this, are you interested?' and we put our hands up straight away, not just because we wanted to do it but we admired his capability and charisma.
"He and Derek deserve to take much of credit for leading a team of pretty haphazard broadcasters. Of course, when it came to sticking at it for that long, it also helped we were all in our early 20s - you're bulletproof at that age," Magan says, laughing.
He agrees, when asked to explain why Radio Hauraki's founding continues to fascinate after almost half a century, "it does get people's imaginations running, that's for sure. I think it's because it remains one of the outstanding stories of political action in New Zealand."
Magan hopes his grandchildren's generation watch Pirates of the Airwaves and "find out what we did, how we did it and why.
"And I hope it shows them they don't have to sit back on Facebook and let the world come to them, that they can take themselves to the world and actually change things."
Pirates of the Airwaves screens July 27, 8.30pm, on TV One.
