There still would have been an outcry because she would have been applying "a thug's veto" to free speech on campus. If all it takes to cancel an event is for someone to threaten violence, then free speech is on very thin ground indeed. We look to our universities to be defenders of free speech - to cave in at the first sign of trouble is no glorious defence.
But that is not all that she said.
In cancelling the event Thomas went on to make a number of other remarks in her press release. I quote:
Professor Thomas says she supports free speech on campus, but totally opposes hate speech. "Mr Brash's leadership of Hobson's Pledge and views he and its supporters espoused in relation to Māori wards on councils was clearly of concern to many staff, particularly Māori staff. Whether those views would have been repeated to students in the context of a discussion about the National Party may seem unlikely, but I have no way of knowing. In my opinion the views expressed by members of Hobson's Pledge come dangerously close to hate speech. They are certainly not conducive with the university' strategy of recognising the values of a Tiriti o Waitangi-led organisation."
This is what caused the outcry.
The clear implication was that Brash's views were not welcome on campus. Apparently, it's a heinous crime not to agree with creating Maori wards on councils - though most referenda on the questions have shown a clear majority of New Zealanders don't agree either.
It is not an unreasonable conclusion to draw that Thomas's Health & Safety concerns, or ready acquiescence to the "thug's veto", were a convenient fig leaf to cover her primary motivation.
It may or may not be the case, we'll never know. But it was her ambiguity around her reasons for the cancelling the event that led to the trouble. I have no doubt that, as Professor McCutcheon says, it is difficult to resolve the competing interests of groups that demand the right to say offensive things and the demands of others who don't want to hear those offensive things. But the incident struck a chord because there is a suspicion that universities are in danger of becoming intolerant places, where people are all expected to accept certain propositions.
Many throughout the university system instead seem to have concluded that to raise a head above the parapet to debate contentious ideas is not worth the risk. And that is the real danger.
So, yes, reconciling the conflicting desires among the student body is tricky. But the broader challenge for the university sector is to preserve and promote genuine diversity of thinking within the universities and to create an atmosphere which is safe to challenge the dominant prejudices of the times.
• Paul Goldsmith is a National MP.