Moments before a drunken Dave Fane let rip with a string of profanities and racist insults in front of an audience of startled radio personalities and advertising big wigs, he made an off-the-cuff joke.

The Flava breakfast host and actor, known for roles in Outrageous Fortune and Sione's Wedding, turned to John Tamihere and said: "You know what? They want me to perform like a Pacific Island chimpanzee - here goes."

And perform he did, not like a cute chimpanzee but like a burbling bigot, stunning his captured targets of advertising agency people at the inaugural Radio Roast.

First came the profanities - the ad men and women roared with laughter at being called motherf*****s. But the raucous atmosphere within the Northern Club walls became more subdued as Fane's roast material turned septic.

"You've all got f****** Aids, c****," Fane slurred at his audience, waving a bottle of Heineken.

And a few moments later: "I want to eat you, but I won't because I don't want to get HIV. Would you roast an HIV person? You'd roast them because they're expendable. Like the Jews. Hitler had a right, you know."

Tamihere, watching the audience from the front, says reaction was pretty much split down the middle - half were laughing, the other half gaped in jaw-dropping astonishment.

"Some people looked horrified, violated ... some of them were saying 'What? He didn't say that, did he?'."

They looked like "possums caught in the headlight".

Yet afterwards no one reacted. No one protested, or tackled Fane after his expletive-ridden diatribe. Neither did the bloggers, tweeters or radio talkback hosts take on Fane in the days after the roast - except for Fane himself who tweeted the following day: "Did a work gig last night, hope I still gotta job this morning."

Just what other celebs in the audience thought that night is hard to ascertain. Mike Hosking, and Willy de Wit did not respond to phone messages or emails from the Herald on Sunday. Paul Ego declined to comment. Jason Gunn called back but did not respond to messages after that.

Jeremy Corbett emailed twice to say he was too busy filming 7 Days to respond and was then going on holiday. On the night, Corbett said about Fane's offensive outburst, "That's just Dave. He featured in an episode of Deal or No Deal once but it was so offensive it never aired."

Radio newsreader and TV presenter Kate Hawkesby was reluctant to talk specifically about the roast, saying she was "uncomfortable" because she and Fane shared the same employers which put her in a "precarious" position.

The silence after Fane's performance turned to murmurings two days later when the Herald on Sunday's gossip columnist, Rachel Glucina, made calls.

This week Radio Network's chief executive John McElhinney admitted that in hindsight he was too slow to react over Fane's transgressions. When Fane came off stage the network boss was photographed with Fane for Spy and, with the big man's arm slung over McElhinney's shoulder, there was no sign of tension between the two.

On the night McElhinney said only that Fane's performance was a "little more out there than I expected". It wasn't until five days later that Fane was suspended for a week from his radio spot - the day after a story appeared in the Herald on Sunday.

This week McElhinney said he was caught unaware by Fane's performance and was "shocked" by it. He "absolutely" agreed that Fane went too far. As Fane let rip on stage that Wednesday night, the radio boss moved to the back of the room to judge audience reactions.

"Fifty per cent of the room was with him and 50 per cent of the room was definitely not with him."

But, like others there, McElhinney didn't tackle Fane about it because "it wasn't appropriate for a number of reasons".

Neither did he speak directly to Fane later that week, instead asking his director of programming to talk to Fane on the Friday - two days after the roast.

"With the wisdom of hindsight I believe I should have taken more action on the Thursday."

This week Fane and McElhinney, on behalf of Radio network, sent letters of apology to the New Zealand Jewish Council and the NZ Aids Foundation.

Last Sunday after the story broke, Fane went on TV3 with an emotional and subdued apology. Few watching the large man, at times close to tears and repeatedly saying he was "so very sorry" for the offence he had caused, would have doubted he was sincere.

"They were dumb words said by a dumb man," Fane said softly, "and they are no way the sort of words I believe in ... that doesn't make it any better ... I just feel so gutted, it was stupid, a stupid thing to say ..."

And the final words, as though muttering to himself: "What an arsehole eh ... what an arsehole."

As apologies go, Fane's was up there - heartfelt, shamefaced, no attempt at justification.

And, unlike the apologies of Tiger Woods (multiple affairs), Tony Veitch (assaulting his ex), and Mel Gibson (anti-Semitic and sexist remarks made after his arrest for drink-driving in 2006), it was unscripted.

McElhinney and others who know Fane say the racist and anti-HIV remarks were out of character.

McElhinney: "What happened on that night was not Dave Fane."

While Fane contemplates the fatal mixture of nerves, too much to drink and a runaway mouth during his days off air, there's a certain amount of sympathy for the likeable Flava host.

Radio host Marcus Lush, in a blog last week, said he'd done plenty of "terrifying" public gigs himself.

"For Dave, this gig was a hiding to nowhere ... So he [Fane] turns up to the debate slightly under-prepared, things don't go well, the crowd isn't paying attention, he has a bit to drink, he feels he is failing a bit, he is not holding the audience's attention and so he drops in some of his more radical material."

But there is a difference between radical and racially offensive material.

Tamihere: "Here's the problem with Dave, he didn't roast them, he nuked them."

And Tamihere should know. Five years ago the former Labour MP caused an uproar when he told investigative journalist Ian Wishart during an interview that he was "sick and tired of hearing how many Jews got gassed". In the same interview he called Cabinet minister Chris Carter "queer".

This week Tamihere said Fane went places he should never have gone, the Holy Cows of comedy, he says.

"It's about taste and it's about how far you go in a roast ... that's where your moral compass comes in. It is not illegal." But he also argues context. Fane was asked to do a job and he did it.

But Sam Sefuiva, of the Human Rights Commission, dismisses the context argument: "If we do nothing it either gets uglier or the next person who does it will know that that's the benchmark."

Edge radio hosts Carl Fletcher and Vaughan Smith, in the audience that night, say they are sure people would have walked out had Fane carried on much longer.

Instead, they say, no one really knew what to do.