The first I knew about it was a three-word message. I’d just switched on my phone — it was the children’s half-term, and I was up later than usual — to see a short text from a Guardian colleague. “Badge of honour!”

I had no idea what it referred to and was similarly baffled by several more messages in the same vein, all equally opaque. Eventually, I discovered they were referring to a just-released Vice documentary about Jeremy Corbyn, a 30-minute fly-on-the-wall film following the Labour leader, in which he was seen describing a Guardian column I’d written as “utterly disgusting subliminal nastiness.”

That was back in June 2016; the column had appeared the previous March. It all happened nearly four years ago. And yet the memory of it returned this week, thanks in part to the journalist Oz Katerji, who’s producing a fascinating podcast series, Corbynism: the post-mortem. The first episode focused on Labour’s antisemitism crisis, and Katerji brought together activist Adam Langleben, human rights lawyer Adam Wagner and me to talk about it.

Langleben was asked at what point he realised that Corbyn himself might have an antisemitism problem, and he answered that the watershed for him was that Vice film. Naturally Katerji asked me about it, unaware perhaps that I had never spoken, written or so much as tweeted about it before.

I’m not quite sure why I’d said nothing. Part of it was a vague journalistic scruple that no matter how interesting we might find ourselves, we journalists are never the story. Part of it was a desire to seem unbothered by this unusually direct attack on me by the Leader of the Opposition, as if I’d barely noticed it.

In truth, though, it left me quite shaken. It’s unnerving to see yourself torn into by a frontline politician — the man who would be prime minister — with such venom. Also, Corbyn’s remarks came in a phone call with his most senior aide, Seumas Milne, who happened to be an old colleague of mine. Our politics were miles apart, but we’d always been friendly: he’d been in my home, we’d visited each other when we were ill. And yet in the phone call on the Vice film, it’s clear that Milne responds to Corbyn’s “utterly disgusting” riff by saying that I’m “not a good guy.”

Perhaps I should have been able to transcend the personal discomfort I felt, because Langleben was right: this was a telling moment in the Corbyn story.

Why? One clue is provided by that original Guardian column of mine. Given the intensity of the Labour leader’s response, you might imagine it to be a lacerating screed, dripping with vitriol. But reading it now, what’s striking is not how aggressive it is, but how mild. Its tone is one of sorrow rather than anger, explanation rather than accusation.

It sets out all the ways in which criticism of Israel or Zionism can be perfectly legitimate, offering only a gentle word of warning about the dangers of straying into suspect territory. Of Corbyn himself, it explicitly declares that “No one accuses him of being an antisemite.”

Instead, it says, “many Jews do worry that his past instinct, when faced with potential allies whom he deemed sound on Palestine, was to overlook whatever nastiness they might have uttered about Jews.” Given what was to come out in the following months and years, I’m almost embarrassed by its emollience.

And yet it was too much for Corbyn. A plea from a Jewish writer for a tad more understanding of the anxieties of his fellow Labour-supporting Jews was denounced as “utterly disgusting.” Later in the film, Corbyn learns of Ken Livingstone’s now-notorious remarks about Hitler “supporting” Zionism. The film-maker presses the party leader for a reaction. The harshest condemnation he can muster is that Livingstone’s comments might have been “inappropriate.” The proof was there, in that documentary, that Corbyn found the accusation of antisemitism far more offensive than antisemitism itself. What’s more, he didn’t regard such an attitude as something to hide: he said it all with a camera in his face.

We can linger too on that word “subliminal.” Such an odd choice, and so revealing. Why would he describe a newpaper column by a Jewish journalist as “subliminal”, defined as “affecting someone’s mind without their being aware of it”? Why would he reach for the notion that Jewish concern about antisemitism relies on trickery and manipulation, operating through hidden subterfuge? In dismissing a complaint of antisemitism, he had dipped into the vocabulary of antisemitism.

One last thing: it was curiously out of character. Corbyn rarely attacks anyone in acid language. He barely took aim at Theresa May or Boris Johnson, and certainly not in personal terms. But he took aim at me that day. I’ve sometimes wondered if that acted as a signal for some of Corbyn’s most devoted supporters to regard me as an acceptable receptacle for their fury, a target for social media rage sanctioned by the man himself. Over the next three and a half years, it often felt that way.

Soon Corbyn will be gone. But the problem he personified, exacerbated and did so little to address, will endure unless his successor admits its scale and its depth. There’s nothing subliminal about that: I’m saying it out loud.

Jonathan Freedland is a Guardian columnist