MONTREAL – These things happen all the time: A prominent lawmaker squires a local constituent through the halls of a legislative body, celebrates him as a hero, and stands by as his guest receives waves of appreciative applause.

But things like the episode that unfolded in the past several days in Canada, with timing like this, do not happen all the time, and indeed should not happen at all.

In this case, as Jews across Canada were preparing for the solemnities of Yom Kippur, the Speaker of the Canadian House of Commons introduced to his colleagues one Yaroslav Hunka, who received the customary hero’s welcome on Parliament Hill, except that if he were a hero to anyone, it was probably to Adolf Hitler. Mr. Hunka, who is 98, received two standing ovations from the lawmakers. Hunka was a member of the First Ukrainian Division during World War II. That division also was known as the 14th Waffen Grenadier Division of the SS.

This was a gaffe – more to the point, it was a crime against human memory if not against humanity itself – for the ages.

The reaction took a day or so to gather, but once it did, the eruption of outrage was like the wake issuing from a great ship, flowing, in this case, across Canada’s Jewish community and flooding into parliamentary districts from coast to coast. There were immediate cries for the resignation of the Speaker, an otherwise rather colorless character named Anthony Rota, who, in fairness, has a spotless record on issues of human rights. He finally relinquished his post Tuesday after a chorus of demands that issued slowly, and then with irresistible force, from leaders of his own Liberal Party and opposition Conservative Party figures, along with members of the New Democratic Party (known colloquially as the NDP) and the Bloc Québécois.

One question bounced off the walls of the West Block: How could this have happened?

Of course, that question goes to the heart of the Holocaust itself, but, more than three-quarters of a century later, in the peaceable kingdom of Canada, it retained its special power – and it prompted a strong reaction across the border as well. “The fact that a veteran who served in a Nazi military unit was invited to and given a standing ovation in Parliament is shocking,” the Friends of Simon Wiesenthal Center for Holocaust Studies said in a statement.

“This is an egregious error on the part of the Speaker but we don’t discern any intentional malice on his part,” said Shimon Koffler Fogel, who heads the Center for Israel and Jewish Affairs, the advocacy agency of Jewish Federations across Canada. “It was a shockingly careless mistake, and he’s taken responsibility for it,” said Mr. Fogel, in an interview minutes before Mr. Rota resigned.

This episode, occurring while Ukrainian President Volodymyr Zelensky was in the Commons chamber, prompted applause from Prime Minister Justin Trudeau and Mr. Zelensky himself. It occurred two days before the beginning of Yom Kippur, when rabbis across Canada had long finished their sermons for Kol Nidre and for Monday services. So, while the subject was top of people’s minds during Yom Kippur, it generally was not the leitmotif of rabbinical remarks this week. Almost certainly it will be for the first days of Sukkot.

Mr. Rota swiftly apologized. “It was my decision and I apologized profusely,” he told members of the House Monday. “I cannot tell you how regretful it is. It may not be good enough for some of you, and for that I apologize.”

In truth, it was not good enough.

Moments before Mr. Rota stepped down, Mr. Trudeau called the moment “deeply embarrassing for the House and for Canada.” The opposition leader, Pierre Poilievre of the Conservative Party, said the incident “brought shame on Canada,” adding that the spate of apologies being issued throughout Ottawa “does not excuse Justin Trudeau’s failure to have his massive diplomatic and intelligence apparatus vet and prevent honoring a Nazi.”

As in the United States, the specter of Nazi war criminals settling into normal lives in Canada has been a constant theme.

“The appearance of this man before Parliament brings up a question that has been vexing for decades,” Mr. Fogel said in the interview. “We know there are individuals who emigrated to Canada from Europe following the Second World War who had possible links to the Nazi regime or the SS or were collaborators.”

In 1985, Prime Minister Brian Mulroney established the Commission of Inquiry on War Criminals in Canada, headed by Appeals Court Justice Jules Deschênes, that examined reports that, among many others, Joseph Mengele was living in Canada. The Commission found evidence in 20 cases, and soon thereafter, Canada amended its Criminal Code to allow putting suspected Nazi war criminals on trial. Only one suspect, Imre Finta, was ever prosecuted but was found not guilty of holding nearly 9,000 Jews in a Hungarian factory before they were dispatched to Auschwitz and Stasshof death camps.

There was one other element of fallout. The episode immediately was employed by officials in Moscow for propaganda purposes as part of Russia’s war against Ukraine. From the start, Russian President Vladimir Putin has been arguing, without evidence, that his “special military operation” was designed to “de-Nazify” Ukraine.

“Such sloppiness of memory is outrageous,” Kremlin spokesman Dmitry Peskov said this week. “Many Western countries, including Canada, have raised a young generation that does not know who fought whom or what happened during the Second World War. And they know nothing about the threat of fascism.”

That may be the only remark issuing from Moscow since the invasion of Ukraine that contains a grain of truth – in this case, alas, sad but true. Θ

David M. Shribman, who won a Pulitzer Prize as Washington bureau chief of the Boston Globe, is executive editor emeritus of the Pittsburgh Post-Gazette and teaches at Carnegie Mellon University and McGill University.