Edited for clarity/streamlining links.
An academic making a controversial claim is a means of advancing his credentials, an example of his ability to look at facts uniquely, or being able to break away from "established thought" or bring a fresh perspective to well-worn paths. There is nothing wrong in any of that.
In the realm of academia.
A politician making a controversial claim is (usually) a means of distinguishing his position from others, to offer an alternative to the establishment, and to bring a fresh approach, and fresh solutions to intransigent issues or problems. There is nothing wrong with that.
Sometimes, it even works.
But most of the time it is grandstanding.
As H. L Mencken (sort of) said, "For every complex problem there is an answer that is clear, simple, and wrong."
The question of "Fake news" or "deliberate online falsehood" is a complex one. There is no simple solution. In the first place, people generally do not even know the difference between Facts, Values, and Opinions.
There are some questions that should be easy to answer. Questions that are based on scientific fact. Like, Climate Change. Or whether vaccines cause autism.
Yet, people are not convinced by facts, by science, by scientific reviews and studies.
And then, here are some things that are value-laden, or are morally "right" or "wrong" if you accept certain values. It does not make what you think is "right" to be (factually) "true" or what you think is "wrong" to be (factually) "false". But people cannot even separate right/wrong from true/false.
The study of History at tertiary (University) level will eventually lead one to a B.A. in History (if I am not mistaken).
Not a B.Sc.
History is an "art", an interpretive discipline. It requires one to sift through old documents, old records, old papers and other evidences. It requires one to understand human nature, understand that narratives are often self-serving or even self-aggrandizing, and memories are often selective, or even faulty. And records are never complete. Official records are precisely that and nothing more.
It is not the TRUTH.
So what happens when a Historian walks into the political realm with his alternative views of history, and his "cheeky" take on Singapore's history? What does he hope to do?
Does he intend to replace the orthodox history as accepted by the "mainstream" historians with his unique interpretation? Does he intend to rewrite history?
Well, he might be that "cheeky" and optimistic. But at the minimum, he should at least get a rise out of the powers that be (i.e. Shanmugam), and have his controversial interpretation of history argued in a public forum.
Mission accomplished! Shanmugam played right into his hands!
Not that he (Shanmugam) had any choice. The historian, having entered the political realm with his unorthodox history HAD TO BE TREATED AS A POLITICAL INTERLOPER. And his unorthodox narrative had to be treated as an attempt to upset the political status quo. The Minister then had no choice but to defend the status quo (the orthodox historical narrative).
So the Minister looked like a over-enthusiastic guard dog, and the historian got his objective of having his narrative argued in a public forum.
And Singaporeans get to argue about who is right and who is wrong. Which is largely irrelevant.
From a 2010 news story:
"In academic history, alternative narratives have become the norm rather than an exception. For example, research councils in Britain and the United States are more likely to fund projects that look at marginal or alternative narratives instead of those with state-centric agendas. In the field of historical scholarship, challenging the state has become the intellectual 'in-thing'."
Yes. challenging the state is the "in-thing". But a good historical narrative, even an unorthodox one would be peer-reviewed. In other words, other historians, with the discipline of academicians would make the determination.
In the realm of academia.