The man who wrote to Massey University with concerns over Don Brash's event, before the cancellation, says he has been targeted by critics.
Dr Brash, a former National leader and Reserve Bank governor, was due to speak at Massey University's Politics Society in Palmerston North.
Karl Pearce wrote to Massey University vice-chancellor Jan Thomas saying the event could be used as a platform for separatist and supremacist hate speech.
While Mr Pearce did not specifically ask for Dr Brash to be banned, Prof Thomas cancelled the event citing safety concerns.
The decision came at a time of heightened tension over free speech and hate speech prompted by the visit of Canadian alt-right speakers Lauren Southern and Stefan Molyneux to New Zealand, Prof Thomas said.
ACT Party leader David Seymour called for Ms Thomas to stand down over her decision, while Prime Minister Jacinda Ardern called it an "overreaction".
Mr Pearce told Morning Report Mr Seymour's reaction to the letter had created safety concerns for himself.
"Honestly after the fact that David Seymour took my letter, my personal letter, which was public and ran with it and completely made a huge outrage out of it, both myself and Jan [Thomas] were from there on threatened," he said.
"The Act [Party] members and not necessarily Act itself, but a lot of David Seymour's followers totally used that as a reason to incite safety concerns.
"They personally targeted me... I sit on a number of not-for-profit organisations, some of them have had threats."
Massey University Deputy Pro Vice Chancellor Chris Gallavin told Morning Report the letter by Mr Pearce was "right, rational and civil".
"Others have jumped on the bandwagon in a sense and blown it up to more than what I think it is," he said.
However, the cancellation of Dr Brash's event went against the important role universities played in free speech, Mr Gallavin said.
"A university plays a very important role in modelling civil and rational discussion and debate over tough topics in an environment where in the world we seem to have lost our ability to disagree well.
"Without [debate and discussion] no amount of police or security will be able to protect us from the fallout of ever-increasing polarisation of views."
However, Mr Gallavin said there were boundaries to freedom of speech too.
"Unfortunately freedom of speech, or fortunately, we do have something called freedom of speech that allows people to say unpopular things ... and there's limits on that ... and hate speech is one of the limits."
'The Streisand effect'
Critic magazine editor Joel MacManus said that Massey's action was similar to what happened recently when a controversial copy of Critic was banned and destroyed.
"You try to ban something people want it more ... That's exactly the same thing that happened here and Massey should have predicted that."
AUT Senior lecturer Ella Henry told Morning Report the university's actions stimulated more people to speak up.
"I do think that Massey has probably created more of a spin for Don Brash than actually try to make a moral stand," she said.
She also compared it to when his criticism of the use of te reo Māori on RNZ actually resulted in more people standing up for the language.
"What I think is most intersting about Don Brash's stance on te reo is that his decision was so extraordinary that it started a conversation that continues today ... he's got more people talking about why te reo is important."