Members of the Organisation of Ukrainian Nationalists, known as the OUN, had indeed been killed at Babi Yar - the group fought both with and, subsequently, against, the Germans - but the sign sat right alongside panels telling the story of the Jewish victims.
Mentioned by name as a victim was Ivan Rohach, the editor of Ukrainske slovo, a collaborationist newspaper.
Ukraine has come a long way from the Communist period, when mourning the deaths of the Jews slaughtered here was suppressed and subsumed into the narrative of Soviet victimhood but, in the period following the Maidan revolution in 2013, renewed moves to rehabilitate Ukrainian collaborators have stained efforts to get to grips with the nation's past.
More than 33,000 Jews were murdered in two days here in 1941 in what has come to to be known as the "Holocaust of bullets".
Eduard Dolinsky, the director of the Ukrainian Jewish Committee, an advocacy group, said that having to sit in front of the memorial with those who would honour the OUN was "awkward and terrible situation".
Sitting next to the stage where world leaders were shortly due to speak about the legacy of Babi Yar, Mr Dolinsky complained about the presence of members of the modern, revived, OUN in the planning committee that organised the commemorations.
This was, Mr Dolinsky said, merely "the continuation of the Soviet tradition" of minimising the unique Jewish character of the site.
And while many of the speakers, including Ukrainian President Petro Poroshenko, did mention the uniquely Jewish nature of the site, the presence of collaborators and antisemites at the service left a sour taste.
Speaking before the Verkhovna Rada - the Ukrainian parliament - on Tuesday, Israeli President Reuven Rivlin reminded his audience of the role of Ukrainian collaborators at Babi Yar, challenging recent attempts to glorify the OUN and its offshoot, the Ukrainian Insurgent Army (UPA).
"Many of the collaborators were Ukrainian, among the most notorious the members of the OUN, who carried out pogroms and massacres against the Jews and in many cases handed them over to the Germans," he said. "It is true, there were more than 2,500 Righteous Among The Nations, lone candles who shone in the darkness. Yet the majority remained silent."
Praising recent efforts towards democratisation in the country, Mr Rivlin nevertheless said it was incumbent on Ukrainians to "recognise antisemitism as it was and as it is found today, and not rehabilitate or glorify antisemites".
A bill declaring members of the UPA to be heroes of the fight for national independence was passed by the Rada last year.
Suppressed under the previous administration of ousted pro-Kremlin President Viktor Yanukovych, the glorification of the OUN and the UPA has continued apace under Mr Poroshenko and Volodymyr Viatrovych, the director of the state-sponsored Institute for National Memory.
Mr Viatrovych has long argued that Ukrainian militant organisations were not collectively complicit in the Holocaust and that, to the contrary, many of its fighters actively saved Jews.
Responding to Mr Rivlin's speech, the influential government historian accused the Israeli President of peddling the "Soviet myth of OUN participation in the Holocaust".
Paul Podobyed, a fellow at the Ukrainian government institute, went even further, asserting that Mr Rivlin's statements were equivalent to a Ukrainian leader telling the Knesset that Jews were responsible for the Holodomor, the famine brought about by the Soviets' collectivisation of farms which left millions of Ukrainians dead. This, it must be said, is a conspiracy theory that does exist in some circles in Ukraine.
Mr Rivlin's speech, Mr Dolinsky said, "caused a wave of antisemitic speech on the Ukrainian internet. This is the state of affairs we Ukrainian Jews have to face now." And sadly, there was no official condemnation of Mr Viatrovych's statements.
Despite the controversies, there are many who see Ukraine's willingness to commemorate Babi Yar as a sign of progress, especially after years of failed initiatives to create a new memorial at the site.
Speaking at a separate ceremony earlier on Thursday to mark a deal between several Jewish oligarchs and the Ukrainian government to build a new memorial centre at Babi Yar, Chief Rabbi Yaakov Dov Bleich said the fact that his colleague Rabbi Moshe Azman had been invited to blow the shofar in the Rada in memory of the victims would have been unthinkable a few years ago.
"Until today, the history of Ukrainians has always been written by others. One part of the puzzle of Ukrainian history was the Holocaust, and a big part of that was Babi Yar. The challenge for Ukrainians today is to understand it and write an objective history."
Earlier this year, a joint Ukrainian government-civil society committee invited architects to submit new designs for the Babi Yar memorial site ahead of this week's events. Among the guidelines - later rescinded - was the call for applicants to resolve the "problem" of the "discrepancy between the world's view and Jewry's exclusive view of Babi Yar as a symbol of the Holocaust."
While most of the accusations of Ukrainian antisemitism made by the Russian press are false, the country must fix the way it approaches its history. Until then, the words of its leaders will ring hollow.
